Browsing Articles publicats (Matemàtica) by Issue Date
Now showing items 1-20 of 311
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Algunas propiedades de un algoritmo de clasificación piramidal
(Instituto Nacional de Estadística, 1995)En este trabajo se enuncia un Algoritmo de Clasificacián Ascendente Piramidal y se establecen algunas de sus propiedades, que ponen de manifiesto la mejora que éste supone respecto a otros algoritmos establecidos con ... -
Empirical significance test of the goodness-of-fit for some pyramidal clustering procedures
(Institut d'Estadística de Catalunya, 1995)Through a series of simulation tests by Monte Carlo methods, some aspects relating to the inference concerning pyramidal trees built by the maximum and minimum methods are considered. In this sense, the quantiles of the ... -
Pirámides indexadas y disimilaridades piramidales
(Institut d'Estadística de Catalunya, 1995)En este trabajo se pretende una formalización de las bases matemáticas sobre las que se amparan los modelos de clasificación y representación piramidal, estableciéndose para ello una relación entre los conceptos de pirámide ... -
Behaviour of the current in a membrane-covered disc microelectrode under steady-state conditions
(The Royal Society of Chemistry, 1996)The inlaid disc electrode covered with a membrane can be modelled as a system with axial symmetry containing several parallel layers with different permeabilities. A recent solution of the steady state under diffusion ... -
Integrability of a linear center perturbed by a fourth degree homogeneous polynomial
(Universitat Autònoma de Barcelona. Departament de Matemàtiques, 1996)In this work we study the integrability of a two-dimensional autonomous system in the plane with linear part of center type and non-linear part given by homogeneous polynomials of fourth degree. We give sufficient conditions ... -
The null divergence factor
(Universitat Autònoma de Barcelona. Departament de Matemàtiques, 1997)Let (P, Q) be a C 1 vector field defined in a open subset U ⊂ R2 . We call a null divergence factor a C 1 solution V (x, y) of the equation P ∂V + Q ∂V = ∂P + ∂Q V . In previous works ∂x ∂y ∂x ∂y it has been ... -
Integrability of a linear center perturbed by a fifth degree homogeneous polynomial
(Universitat Autònoma de Barcelona. Departament de Matemàtiques, 1997)In this work we study the integrability of two-dimensional autonomous system in the plane with linear part of center type and non-linear part given by homogeneous polynomials of fifth degree. We give a simple characterisation ... -
Concepciones de los profesores sobre la enseñanza de las ecuaciones diferenciales a estudiantes de química y biología: estudio de casos
(Universitat Autònoma de Barcelona. Institut de Ciències de l'EducacióUniversitat de València, 1997)Intending to quest about the conceptions math teachers hold about how to teach Differential Equations to chemistry and biology students, we have devised a research tool which allows us to derive relevant information. We ... -
Analytical solution for the steady-state diffusion towards an inlaid disc microelectrode in a multi-layered medium
(Elsevier Science, 1997)The rigorous analytical expression for the steady-state diffusion-limited current produced by an electroactive species diffusing towards an inlaid disc electrode through a multi-layered medium (such as the membrane covered ... -
Voltammetric currents for any ligand-to-metal concentration ratio in fully labile metal-macromolecular complexation. Easy computations, analytical properties of the currents and graphical method to estimate the stability constant
(Elsevier, 1999)In order to enable a wider use of voltammetric methods in speciation analysis, it is convenient not to be restricted by ligand excess conditions. This work assumes labile ideal complexation of a metal ion by a ligand, ... -
A survey of isochronous centers
(Edicions de la Universitat de Lleida, 1999) -
Voltammetric lability of metal complexes at spherical micorelectrodes with various radii
(Elsevier, 2001)The size of a microelectrode can have a dramatic impact on the relative importance of the diffusional and kinetic contributions to the voltammetric current of an electroactive metal ion in a complexing medium. Decreasing ... -
La enseñanza de estrategias de resolución de problemas matemáticos en la ESO: un ejemplo concreto
(Universitat Autònoma de Barcelona. Institut de Ciències de l'EducacióUniversitat de València, 2001)Within this article is included a description and justification of a didactical sequence to improve the learning of problem solving strategies of Secondary Education students. The design of the didactical sequence is guided ... -
Evaluation of the Koutecký-Koryta approximation for voltammetric currents generated by metal complex systems with various labilities
(Elsevier, 2002)The voltammetric response of metal complex systems with various labilities is analyzed by rigorous numerical simulation with the Finite Element Method of the time-dependent concentration profiles of the different species. ... -
Análisis de las actitudes y conocimientos estadísticos elementales en la formación del profesorado
(Sociedad Andaluza de Educación Matemática "Thales", 2002) -
Lability and mobility effects on mixtures of ligands under steady-state conditions
(Royal Society of Chemistry, 2003)Analytical solutions for the steady-state flux arriving at an active surface from a mixture (in which one active species reacts with non-active ligands in the medium) can be helpful in a variety of problems: voltammetric ... -
Actitudes hacia la estadística y su evaluación
(2003)En este trabajo analizamos la problemática de la evaluación de las actitudes de los profesores hacía la Estadística. Es ésta una materia de reciente incorporación al curriculum de Educación Primaría y los profesores que ... -
Rendimiento matemático en contextos bilingües: análisis de la incidencia de algunas variables del contexto socio-educativo
(Universidad de Murcia. Servicio de PublicacionesAsociacion Interuniversitaria de Investigacion Pedagógica (AIDIPE), 2003)El trabajo que se presenta en este artículo se sitúa en el contexto bilingüe de la provincia de Lleida en la que coexisten dos lenguas en contacto, el catalán y el castellano, si bien existe un predominio de uso familiar ... -
Concepciones y creencias de los profesores universitarios de matemáticas acerca de la enseñanza de las ecuaciones diferenciales
(Universitat Autònoma de Barcelona. Institut de Ciències de l'EducacióUniversitat de València, 2003)La investigación que aquí presentamos es una aproximación a las concepciones y creencias de los profesores universitarios de matemáticas acerca de la enseñanza de las ecuaciones diferenciales en estudios científico-experimentales. ... -
AGNES: a new electroanalytical technique for measuring free metal ion concentration
(Elsevier, 2004)AGNES (absence of gradients and Nernstian equilibrium stripping) is a stripping technique consisting of two conceptual steps: (i) application of a potential program (e.g. a step at a fixed potential) generating a known ...