Search results for "matemàtiques"
showing 10 items of 55 documents
Facultat de Ciències Matemàtiques
2008
La Universitat de València t'obri les seues portes. En les seues Facultats i Escoles Universitàries descobriràs una àmplia oferta d'estudis, equipament docent d'última tecnologia, instal·lacions esportives i culturals i una completa xarxa de biblioteques. Tot el que necessites per a accedir a una formació integral que garantisca el teu futur professional.
The identity type weak factorisation system
2008
We show that the classifying category C(T) of a dependent type theory T with axioms for identity types admits a non-trivial weak factorisation system. We provide an explicit characterisation of the elements of both the left class and the right class of the weak factorisation system. This characterisation is applied to relate identity types and the homotopy theory of groupoids.
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 …
Consumo de substancias durante el embarazo y dimensiones de personalidad
2020
Este estudio evalúa los patrones de consumo de substancias durante el embarazo y las dimensiones de personalidad asociadas, en una muestra multicéntrica de 1804 mujeres de población general. En el 2-3 día posparto, completaron una entrevista auto-administrada sobre el consumo de alcohol, tabaco, cafeína, cannabis, cocaína, opiáceos, drogas de diseño, además de variables socio-demográficas, obstétricas/reproductivas, historia psiquiátrica previa, apoyo social durante el embarazo y el cuestionario de personalidad de Eysenck (EPQ-RS). Se generaron modelos de regresión logística múltiple. La prevalencia del consumo fue del 50% (N=909): 40% cafeína, 21% tabaco, 3,5% alcohol, y 0,3 cannabis. Las …
Feasibility issues in static output-feedback controller design with application to structural vibration control
2014
Recent results in output-feedback controller design make possible an efficient computation of static output-feedback controllers by solving a single-step LMI optimization problem. This new design strategy is based on a simple transformation of variables, and it has been applied in the field of vibration control of large structures with positive results. There are, however, some feasibility problems that can compromise the effectiveness and applicability of the new approach. In this paper, we present some relevant properties of the variable transformations that allow devising an effective procedure to deal with these feasibility issues. The proposed procedure is applied in designing a static…
Desenvolupament de les habilitats matemàtiques en alumnat amb espina bífida: revisió bibliogràfica
2019
espanolEl alumnado con Espina Bifida presenta dificultades a la hora de desarrollar sus habilidades matematicas. Se ha analizado con profundidad el concepto de Espina Bifida, para tener una primera vision de lo que este conlleva. Para la revision se ha realizado una busqueda bibliografica en las bases de datos scopus, Dialnet y Google Academico, seleccionando 18 articulos objeto de analisis. Los resultados obtenidos han permitido dar respuesta a los objetivos planteados, obteniendo informacion sobre los enfoques practicos en el area de matematicas con este colectivo y analizar, asi, la efectividad de los mismos. Ademas, en las conclusiones extraidas, se encuentra la necesidad de llevar a ca…
Bayesian classification for dating archaeological sites via projectile points
2021
Dating is a key element for archaeologists. We propose a Bayesian approach to provide chronology to sites that have neither radiocarbon dating nor clear stratigraphy and whose only information comes from lithic arrowheads. This classifier is based on the Dirichlet-multinomial inferential process and posterior predictive distributions. The procedure is applied to predict the period of a set of undated sites located in the east of the Iberian Peninsula during the IVth and IIIrd millennium cal. BC.
Correspondencias de carácteres de grupos finitos
2010
Uno de los problemas fundamentales de la Teoría de Caracteres es la Conjetura de McKay. La Conjetura de McKay afirma que si G un grupo finito, p un primo, y P un p-subgrupo de Sylow de G, entonces existe una biyección entre el conjunto $Irr_{p'}(G)$ de los caracteres complejos irreducibles de G de grado no divisible por p y el conjunto $Irr_{p'}(N)$, donde N es el normalizador de P en G. En general, no se conocen correspondencias canónicas entre estos dos conjuntos, incluso cuando G es resoluble. Sin embargo, bajo ciertas condiciones, sí se han encontrado correspondencias canónicas. En concreto, se han encontrado correspondencias canónicas entre estos dos conjuntos bajo las siguientes hipót…
Learning multiresolution: Transformaciones Multiescala derivadas de la teoría estadística de aprendizaje y aplicaciones
2010
Signal and image processing has become an essential and ubiquitous part of contemporary scienti¯c and technological activity, and the signals and images that need to be processed appear in most sectors of modern life. Signal processing is used in telecommunications, in the transmission of satellite images, and in medical imaging like echography, tomography, and nuclear magnetic resonance. Also it used in applications in Physics, Mechanics and other important issues that nowadays we know and that we will know in the future. Multiscale representations of signals into wavelets bases have been suc- cessfully used in applications such as compression and denoising. In these applications, one esse…
Bayesian correlated models for assessing the prevalence of viruses in organic and non-organic agroecosystems
2017
Cultivation of horticultural species under organic management has increased in importance in recent years. However, the sustainability of this new production method needs to be supported by scientific research, especially in the field of virology. We studied the prevalence of three important virus diseases in agroecosystems with regard to its management system: organic versus non-organic, with and without greenhouse. Prevalence was assessed by means of a Bayesian correlated binary model which connects the risk of infection of each virus within the same plot and was defined in terms of a logit generalized linear mixed model (GLMM). Model robustness was checked through a sensitivity analysis …