Search results for "Matemàtica"
showing 10 items of 147 documents
Automatic regrouping of strata in the goodness-of-fit chi-square test
2019
Pearson’s chi-square test is widely employed in social and health sciences to analyze categorical data and contingency tables. For the test to be valid, the sample size must be large enough to provide a minimum number of expected elements per category. This paper develops functions for regrouping strata automatically no matter where they are located, thus enabling the goodness-of-fit test to be performed within an iterative procedure. The functions are written in Excel VBA (Visual Basic for Applications) and in Mathematica. The usefulness and performance of these functions is illustrated by means of a simulation study and the application to different datasets. Finally, the iterative use of …
Bone Fusion in Normal and Pathological Development is Constrained by the Network Architecture of the Human Skull
2016
The premature fusion of cranial bones, craniosynostosis, affects the correct development of the skull producing morphological malformations in newborns. To assess the susceptibility of each craniofacial articulation to close prematurely, we used a network model of the skull to quantify the link reliability (an index based on stochastic block modeling and Bayesian inference) of each articulation. We show that, of the 93 human skull articulations at birth, the few articulations that are associated with nonsyndromic craniosynostosis conditions have statistically significant lower reliability scores than the others. In a similar way, articulations that close during the normal postnatal developm…
Applying data driven decision making to rank vocational and educational training programs with TOPSIS
2021
Abstract In this paper we present a multi-criteria classification of Vocational and Educational Programs in Extremadura (Spain) during the period 2009–2016. This ranking has been carried out through the integration into a complete database of the detailed information of individuals finishing such studies together with their labor data. The multicriteria method used is TOPSIS together with a new decision support method for assessing the influence of each criterion and its dependence on the weights assigned to them. This new method is based on a worst-best case scenario analysis and it is compared to a well known global sensitivity analysis technique based on the Pearson's correlation ratio.
Situacions d'aula II. Materials docents d'ús interdisciplinari.
2010
Les situacions d’aula són fragments de l’activitat educativa escolar delimitats per l’espai on es realitzen, la duració, les persones i els materials implicats, i la forma en què els uns i els altres estan organitzats. Les situacions que presentem en aquest material són les següents: - «NOTA A LLEDÓ». Escriptura de la resposta a una nota rebuda. ceip La Marina. En aquesta situació, un grup de cinc xiquets del darrer curs d’educació infantil i la seua mestra lligen una «nota» enviada per una altra mestra i la contesten. (Durada de la tasca: 40 min 12 s.) - «EL COR». L’escriptura d’un text dins d’un projecte de treball globalitzat. ceip Lluís Revest. En aquesta situació, un grup de xiquets de…
Situacions d'aula. Materials docents d'ús interdisciplinari
2010
Presentem material de treball per a la formació del professorat d’Educació Infantil i Primària. Les situacions que presentem són les següents: I) «Hi ha boira al Grau de Castelló». L’Escriptura d’una notícia. ceip «La Marina». En aquesta situació, un grup de xiquets i xiquetes d’Educació Infantil, de 5 anys, amb la seua mestra, escriuen de manera col•lectiva una notícia (Durada de la tasca: 28 min.). II) «Pasamos lista». ceip «Lluís Vives». En aquesta situació, un grup de xiquets i xiquetes de 4 anys, junt amb la seua mestra, passen llista al començament de la classe per comprovar que els xiquets han anat a l’escola aquell dia (Durada de la tasca: 5 min. 30 s.) III) «El Caballo». Reelaborac…
A Unifying Framework for Perturbative Exponential Factorizations
2021
We propose a framework where Fer and Wilcox expansions for the solution of differential equations are derived from two particular choices for the initial transformation that seeds the product expansion. In this scheme, intermediate expansions can also be envisaged. Recurrence formulas are developed. A new lower bound for the convergence of theWilcox expansion is provided, as well as some applications of the results. In particular, two examples are worked out up to a high order of approximation to illustrate the behavior of the Wilcox expansion.
A note on a result of Guo and Isaacs about p-supersolubility of finite groups
2016
In this note, global information about a finite group is obtained by assuming that certain subgroups of some given order are S-semipermutable. Recall that a subgroup H of a finite group G is said to be S-semipermutable if H permutes with all Sylow subgroups of G of order coprime to . We prove that for a fixed prime p, a given Sylow p-subgroup P of a finite group G, and a power d of p dividing such that , if is S-semipermutable in for all normal subgroups H of P with , then either G is p-supersoluble or else . This extends the main result of Guo and Isaacs in (Arch. Math. 105:215-222 2015). We derive some theorems that extend some known results concerning S-semipermutable subgroups.
On the supersoluble hypercentre of a finite group
2016
[EN] We give some sufficient conditions for a normal p-subgroup P of a finite group G to have every G-chief factor below it cyclic. The S-permutability of some p-subgroups of O^p(G)plays an important role. Some known results can be reproved and some others appear as corollaries of our main theorems.
Homotopy limits for 2-categories
2008
AbstractWe study homotopy limits for 2-categories using the theory of Quillen model categories. In order to do so, we establish the existence of projective and injective model structures on diagram 2-categories. Using these results, we describe the homotopical behaviour not only of conical limits but also of weighted limits. Finally, pseudo-limits are related to homotopy limits.
Axiomatic characterization of the weighted solidarity values
2014
Abstract We define and characterize the class of all weighted solidarity values . Our first characterization employs the classical axioms determining the solidarity value (except symmetry ), that is, efficiency , additivity and the A-null player axiom , and two new axioms called proportionality and strong individual rationality . In our second axiomatization, the additivity and the A-null player axioms are replaced by a new axiom called average marginality .