Now showing items 1-20 of 39

  • Air quality index revisited from a compositional point of view 

    Jarauta Bragulat, Eusebio; Hervada Sala, Carme; Egozcue Rubí, Juan José (2016-06)
    Article
    Open Access
    The so-called Air Quality Index (AQI), expresses the quality of atmospheric air. The overall AQI is determined from the AQIs of some reference air pollutants, which are calculated by a transform of the respective concentrations. ...
  • Análisis de datos composicionales: aguas, contaminantes, recursos, sociología... 

    Egozcue Rubí, Juan José; Tolosana Delgado, Raimon; Jarauta Bragulat, Eusebio; Ortego Martínez, María Isabel; Díaz Barrero, José Luis (Universitat Politècnica de Catalunya. Escola Tècnica Superior d'Enginyers de Camins Canals i Ports de Barcelona, 2011-11-15)
    Conference lecture
    Open Access
    Los datos composicionales describen las partes de un todo. Se presentan en forma de vectores proporciones, porcentajes, concentraciones químicas etc. y aparecen en multitud de campos de la ciencia y la ingeniería. A pesar ...
  • Análisis y previsión de fenómenos naturales peligrosos 

    Tolosana Delgado, Raimon; Egozcue Rubí, Juan José; Ortego Martínez, María Isabel; Sánchez-Arcilla Conejo, Agustín (Universitat Politècnica de Catalunya. Escola Tècnica Superior d'Enginyers de Camins Canals i Ports de Barcelona, 2011-11-16)
    Conference lecture
    Open Access
    La toma de decisiones referentes al diseño o en sistemas de alerta requieren el estudio de las acciones externas (frecuentemente meteorológicas), la descripción probabilista del sistema (vulnerabilidad, susceptibilidad) ...
  • A posteriori error estimation for standard finite element analysis 

    Díez, Pedro; Egozcue Rubí, Juan José; Huerta, Antonio (1998-09)
    Article
    Open Access
    A new residual type estimator based on projections of the error on subspaces of locally-supported functions is presented. The estimator is defined by a standard element-by-element refinement. First, an approximation of the ...
  • Balances: a new perspective for microbiome analysis 

    Rivera Pinto, J.; Egozcue Rubí, Juan José; Pawlowsky Glahn, Vera; Paredes, Raul; Noguera Julian, Marc; Calle, M. L. (2018-07)
    Article
    Open Access
    High-throughput sequencing technologies have revolutionized microbiome research by allowing the relative quantification of microbiome composition and function in different environments. In this work we focus on the ...
  • Bayesian estimation of the orthogonal decomposition of a contingency table 

    Ortego Martínez, María Isabel; Egozcue Rubí, Juan José (2016)
    Article
    Open Access
    In a multinomial sampling, contingency tables can be parametrized by probabilities of each cell. These probabilities constitute the joint probability function of two or more discrete random variables. These probability ...
  • Bayesian estimation of the orthogonal decomposition of a contingency table 

    Ortego Martínez, María Isabel; Egozcue Rubí, Juan José (2015)
    Conference report
    Open Access
    Contingency tables can be parametrized by probabilities of each cell in a multinomial sampling. These probabilities constitute the joint probability function of the two or more discrete random categorical variables. These ...
  • Bayesian trend analysis for daily rainfall series of Barcelona 

    Ortego Martínez, María Isabel; Gibergans Bàguena, José; Tolosana Delgado, Raimon; Egozcue Rubí, Juan José; Llasat Botija, Maria Carmen (2010-07-15)
    Article
    Open Access
    A Point-Over-Threshold approach using a reparameterization of the Generalized Pareto Distribution (GPD) has been used to assess changes in the daily rainfall Barcelona series (1854–2006). A Bayesian approach, considering ...
  • Bayes linear spaces 

    Van den Boogaart, Karl Gerard; Egozcue Rubí, Juan José; Pawlowsky-Glahn, Vera (2010-12)
    Article
    Open Access
    Linear spaces consisting of $\sigma$-finite probability measures and infinite measures (improper priors and likelihood functions) are defined. The commutative group operation, called perturbation, is the updating given by ...
  • Checking model-data weather hazard occurrence fit in the context of climate change 

    Tolosana Delgado, Raimon; Ortego Martínez, María Isabel; Egozcue Rubí, Juan José; Sánchez-Arcilla Conejo, Agustín (2011)
    Conference report
    Open Access
    In climate change impact studies it is common to run a given response model (from ecosystem changes to wavestorm or landslide occurrence) nested into one of the available long-term Global or Regional Circulation Models ...
  • Classifying wave forecasts with model-based geostatistics and the Aitchison distribution 

    Tolosana Delgado, Raimon; Egozcue Rubí, Juan José; Sánchez-Arcilla Conejo, Agustín; Gómez Aguar, Jesús Javier (2010)
    Conference report
    Restricted access - publisher's policy
  • Climate change in a Point-Over-Threshold model: an example on ocean-wave-storm hazard in NE Spain 

    Tolosana Delgado, Raimon; Ortego Martínez, María Isabel; Egozcue Rubí, Juan José; Sánchez-Arcilla Conejo, Agustín (2010-09-27)
    Article
    Open Access
    A reparametrization of the Generalized Pareto Distribution is here proposed. It is suitable to parsimoniously check trend assumptions within a Point-Over-Threshold model of hazardous events. This is based on considerations ...
  • Compositional data techniques for the analysis of the container traffic share in a multi-port region 

    Grifoll Colls, Manel; Ortego Martínez, María Isabel; Egozcue Rubí, Juan José (Springer, 2019-12)
    Article
    Open Access
    The statistical techniques based on compositional data are applied to investigate the evolution of the traffic share of the container throughput in a multi-port system. Compositional vectors are those which contain relative ...
  • Estimació del pol i de la variància del soroll d'un model AR(1) mitjançant filtratge no lineal 

    Muñoz Gracia, María del Pilar; Martí Recober, Manuel; Egozcue Rubí, Juan José (Universitat Politècnica de Barcelona. Centre de Càlcul, 1988)
    Article
    Open Access
    L'estimació dels paràmetres associats a un procés ARMA es pot plantejar com un problema de filtratge no lineai. Per determinar un estimador recursiu d'aquests paràmetres es deflneix un vector d'estat ampliat que inclou les ...
  • Estimación del parámetro b de Richter a partir de las medidas imprecisas de intensidad epicentral 

    Forcada Plaza, Santiago; Egozcue Rubí, Juan José (Institut d'estadística de Catalunya, 1996)
    Article
    Open Access
    El objetivo de este trabajo es la estimación del parámetro exponencial de Richter que determina la distribución de probabilidad de la variable intensidad de movimientos sísmicos que se producen en una determinada zona. Las ...
  • Evidence functions: a compositional approach to information 

    Egozcue Rubí, Juan José; Pawlowsky Glahn, Vera (Institut d'Estadística de Catalunya, 2018-07-01)
    Article
    Open Access
    The discrete case of Bayes’ formula is considered the paradigm of information acquisition. Prior and posterior probability functions, as well as likelihood functions, called evidence functions, are compositions following ...
  • Exploration of geochemical data with compositional canonical biplots 

    Graffelman, Jan; Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José; Buccianti, A. (2018-07-25)
    Article
    Restricted access - publisher's policy
    The study of the relationships between two compositions is of paramount importance in geochemical data analysis. This paper develops a compositional version of canonical correlation analysis, called CoDA-CCO, for this ...
  • Microbiome datasets are compositional: and this is not optional 

    Gloor, Gregory B.; Macklaim, Jean M.; Pawlowsky Glahn, Vera; Egozcue Rubí, Juan José (2017-11)
    Article
    Open Access
    Datasets collected by high-throughput sequencing (HTS) of 16S rRNA gene amplimers, metagenomes or metatranscriptomes are commonplace and being used to study human disease states, ecological differences between sites, and ...
  • Modelización de la peligrosidad sísmica: aplicación a Cataluña 

    Canas Torres, José Antonio; Egozcue Rubí, Juan José; Miquel Canet, Juan; Barbat Barbat, Horia Alejandro (Centre Internacional de Mètodes Numèrics en Enginyeria (CIMNE), 1996)
    Book
    Open Access
    Un método Bayesiano para la evaluación de la probabilidad de ocurrencia de sismos. Pseudo-aceleraciones del terreno en el subbloque ibero-costero pirenaico. Determinación de las acciones sísmicas de diseño.
  • Modelling compositional change with simplicial linear ordinary differential equations 

    Jarauta Bragulat, Eusebio; Egozcue Rubí, Juan José (2013)
    Conference report
    Open Access