Comentaris de llibres

Comentari del llibre: Lebart, L. Morineau, A.; Fénelon, J.P. Tratamiento estadistico de datos métodos y programas. Marcombo, 1987.Peer Reviewe

Comentaris de llibre

Comentari del llibre: L. Lebart, S. Morineau, J.P.Fénelon. Tratamiento estadístico de datos métodos y programas. Marcombo.Peer Reviewe

Multivariate association of compositional data matrices with applications in comparing hyperspectral images

It is well-known in image processing that, by varying the wavelength, any material reflects and absorbs in a different way the solar radiation. This is registered by hyperspectral sensors, which collect multivariate discrete images in a series of contiguous wavelength bands, providing the spectral curves, which can distinguish between materials. In order to partition a multivariate image in regions belonging to different materials, we need to compare these regions which are previously modelled by using compositional data matrices, where the entries in each row is a statistical discrete distribution of the radiance values (columns). These rows correspond to distinct but contiguos wavelengths. Thus the distribution in a row is very similar to the distribution in close rows. To measure this proximity, we use Hellinger distance between rows, which provides a distance matrix. Given two hyperspectral regions of an image providing two compositional data matrices, we ob- tain the corresponding distance matrices and, by using metric multidimensional scaling, we compute two sets of principal coordinates, which are related by a multivariate association measure based on canonical correlations. We ilustrate this approach comparing some multivariate regions of images captured by hyperspec- tral remote sensors

El programa CANON para IBM360

El programa CANON, escrito en lenguaje Fortran IV para IBM 360, lleva a cabo un análisis canónico completo sobre un conjunto de hasta 15 variables y 30 grupos. Puede admitir 99.999 observaciones para cada variable

Aplicación del análisis canónico al estudio de la mieralización del yacimiento de Osor (Gerona)

El análisis canónico de la mineralización de Osor se ha efectuado con 78 muestras de 7 variables (la cantidad en ppm de los elementos menores siguientes: Ba, Y, Fe, Zn, Cu, Mn, Si). Ha permitido establecer: 1) la mineralización en apariencia homogénea, presenta zonas de génesis diferentes; 2) en cada filón las condiciones de deposición varían con la profundidad; 3) ,dos filones, aparentemente iguales, muestran diferentes procesos genéticos

Evolution of the Dependence of Residual Lifetimes

We investigate the dependence properties of a vector of residual lifetimes by means of the copula associated with the conditional distribution function. In particular, the evolution of positive dependence properties (like quadrant dependence and total positivity) are analyzed and expressions for the evolution of measures of association are given

How good are your fits? Unbinned multivariate goodness-of-fit tests in high energy physics

Multivariate analyses play an important role in high energy physics. Such analyses often involve performing an unbinned maximum likelihood fit of a probability density function (p.d.f.) to the data. This paper explores a variety of unbinned methods for determining the goodness of fit of the p.d.f. to the data. The application and performance of each method is discussed in the context of a real-life high energy physics analysis (a Dalitz-plot analysis). Several of the methods presented in this paper can also be used for the non-parametric determination of whether two samples originate from the same parent p.d.f. This can be used, e.g., to determine the quality of a detector Monte Carlo simulation without the need for a parametric expression of the efficiency.Comment: 32 pages, 12 figure

Assessing associations between the AURKAHMMR-TPX2-TUBG1 functional module and breast cancer risk in BRCA1/2 mutation carriers

While interplay between BRCA1 and AURKA-RHAMM-TPX2-TUBG1 regulates mammary epithelial polarization, common genetic variation in HMMR (gene product RHAMM) may be associated with risk of breast cancer in BRCA1 mutation carriers. Following on these observations, we further assessed the link between the AURKA-HMMR-TPX2-TUBG1 functional module and risk of breast cancer in BRCA1 or BRCA2 mutation carriers. Forty-one single nucleotide polymorphisms (SNPs) were genotyped in 15,252 BRCA1 and 8,211 BRCA2 mutation carriers and subsequently analyzed using a retrospective likelihood appr

A unified approach for representing rows and columns in contingency tables

By using suitable parameters, we present a uni¯ed aproach for describing four methods for representing categorical data in a contingency table. These methods include:correspondence analysis (CA), the alternative approach using Hellinger distance (HD),the log-ratio (LR) alternative, which is appropriate for compositional data, and theso-called non-symmetrical correspondence analysis (NSCA). We then make an appropriate comparison among these four methods and some illustrative examples are given.Some approaches based on cumulative frequencies are also linked and studied usingmatrices.Key words: Correspondence analysis, Hellinger distance, Non-symmetrical correspondence analysis, log-ratio analysis, Taguchi inertiaGeologische Vereinigung; Institut d’Estadística de Catalunya; International Association for Mathematical Geology; Càtedra Lluís Santaló d’Aplicacions de la Matemàtica; Generalitat de Catalunya, Departament d’Innovació, Universitats i Recerca; Ministerio de Educación y Ciencia; Ingenio 2010

Secció docent i problemes

Peer Reviewe