Notes de recerca

Consumo de drogas y vulnerabilidades sociales en adolescentesMulticulturalitat en el comerç de proximita

Preliminary test and Stein-type shrinkage LASSO-based estimators

Suppose the regression vector-parameter is subjected to lie in a subspace hypothesis in a linear regression model. In situations where the use of least absolute and shrinkage selection operator (LASSO) is desired, we propose a restricted LASSO estimator. To improve its performance, LASSO-type shrinkage estimators are also developed and their asymptotic performance is studied. For numerical analysis, we used relative efficiency and mean prediction error to compare the estimators which resulted in the shrinkage estimators to have better performance compared to the LASSO

Evidence functions: a compositional approach to information

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 the Aitchison geometry of the simplex, and have thus vector character. Bayes’ formula becomes a vector addition. The Aitchison norm of an evidence function is introduced as a scalar measurement of information. A fictitious fire scenario serves as illustration. Two different inspections of affected houses are considered. Two questions are addressed: (a) which is the information provided by the outcomes of inspections, and (b) which is the most informative inspection

La Revolució que havia de canviar el món

Cent anys del 1917 Cent anys després de l’assalt del Palau d’Hivern és bo que analitzem com va canviar el món la Revolució Russa. Des del CECOS presentem aquest nou volum de la col·lecció Estudis sobre Conflictes Socials, que explica des de diversos àmbits socials i territoris (des d’Espanya fins a l’Uzbekistan) com va influir en l’esdevenir de la història la revolució bolxevic i com va ser la nova realitat sorgida dels soviets. Amb aquesta finalitat, diversos investigadors analitzen els protagonistes d’aquella etapa i com es van succeir els fets en un món que estava en guerra