Search results for "matemàtica"

Phenotypic Buffering in a Monogenean: Canalization and Developmental Stability in Shape and Size of the Haptoral Anchors of Ligophorus cephali (Monog…

2015

Phenotypic variation results from the balance between sources of variation and counteracting regulatory mechanisms. Canalization and developmental stability are two such mechanisms, acting at two different levels of regulation. The issue of whether or not they act concurrently as a common developmental buffering capacity has been subject to debate. We used geometric morphometrics to quantify the mechanisms that guarantee phenotypic constancy in the haptoral anchors of Ligophorus cephali. Canalization and developmental stability were appraised by estimating inter- and intra-individual variation, respectively, in size and shape of dorsal and ventral anchors. The latter variation was estimated…

Un estudio exploratorio sobre el uso de DragonBox Algebra© como una herramienta para la enseñanza de la resolución de ecuaciones.

2015

Resumen basado en el de la publicación Título, resumen y palabras clave disponibles en español y en inglés Numerosos estudios han analizado el papel del uso de distintos sistemas de representación como una forma de favorecer el aprendizaje de la manipulación de las expresiones algebraicas. La introducción de las nuevas tecnologías en el campo de la educación matemática ha posibilitado la utilización simultánea de distintos sistemas de representación. Han aparecido diversas aplicaciones que utilizan representaciones físicas de la ecuación como podría ser balanzas o áreas para dar significado a las manipulaciones algebraicas. Sin embargo, el uso de modelos reales plantea la dificultad de tras…

On the viability of an algebraic approach to non-monotonic reasoning

1996

Problemas aritméticos verbales en Educación Primaria. Un análisis de guías didácticas

2022

Introducción: Las guías didácticas que complementan a los libros de texto son un material clave que orienta al profesorado sobre algunos aspectos relevantes referentes a la concreción del currículum en el aula, especialmente en la evaluación, uno de los elementos curriculares más relevantes por las repercusiones que conlleva. Metodología: En el presente estudio se analiza el tratamiento de los problemas aritméticos verbales en setenta y ocho pruebas de evaluación incluidas en las guías didácticas de matemáticas publicadas por seis editoriales españolas. El análisis se dirige a conocer cuál es la frecuencia y variabilidad de los problemas frente a otras tareas rutinarias y cuál es su caracte…

Relations between {K, s + 1}-potent matrices and different classes of complex matrices

2013

In this paper, {K,s+1}-potent matrices are considered. A matrix A∈C^(n×n) is called {K,s+1}-potent when K A^(s+1) K = A where K is an involutory matrix and s∈{1,2,3,¿}. Specifically, {K,s+1}-potent matrices are analyzed considering their relations to different classes of complex matrices. These classes of matrices are: {s+1}-generalized projectors, {K}-Hermitian matrices, normal matrices, and matrices B∈C^(n×n) (anti-)commuting with K or such that KB is involutory, Hermitian or normal. In addition, some new relations for K-generalized centrosymmetric matrices have been derived.

Matrices A such that R A = A^{s + 1} R when R^k = I

2013

This paper examines matrices A∈C^(n×n) such that R A = A^(s+1) R where R^k = I, the identity matrix, and where s and k are nonnegative integers with k⩾2. Spectral theory is used to characterize these matrices. The cases s = 0 and s⩾1 are considered separately since they are analyzed by different techniques.

Eilenberg Theorems for Many-sorted Formations

2019

A theorem of Eilenberg establishes that there exists a bijectionbetween the set of all varieties of regular languages and the set of all vari-eties of finite monoids. In this article after defining, for a fixed set of sortsSand a fixedS-sorted signature Σ, the concepts of formation of congruenceswith respect to Σ and of formation of Σ-algebras, we prove that the alge-braic lattices of all Σ-congruence formations and of all Σ-algebra formationsare isomorphic, which is an Eilenberg's type theorem. Moreover, under asuitable condition on the free Σ-algebras and after defining the concepts offormation of congruences of finite index with respect to Σ, of formation offinite Σ-algebras, and of form…