Search results for "Bay"

La teoria que no va morir mai: Com una idea matemàtica del segle XVIII transformà el segle XXI

2014

La regla de Bayes, una teoria senzilla del segle XVIII per a l’avaluació del coneixement, rebé tot de crítiques durant la major part del segle XX, però va ser utilitzada pel Regne Unit i els Estats Units durant la Segona Guerra Mundial i la Guerra Freda. Palomares i València van representar papers importants en el seu desenvolupament durant aquells temps ombrívols. L’ús de la regla està molt estès avui dia en l’àmbit de la computació i en moltes aplicacions més. Per exemple, Bayes s’ha convertit en la clau política per a la presa de decisions basades en dades. La revolució bayesiana ha esdevingut un canvi de paradigma modern per a una era eminentment pragmàtica.

Influence Functions and Efficiencies of k-Step Hettmansperger–Randles Estimators for Multivariate Location and Regression

2016

In Hettmansperger and Randles (Biometrika 89:851–860, 2002) spatial sign vectors were used to derive simultaneous estimators of multivariate location and shape. Oja (Multivariate nonparametric methods with R. Springer, New York, 2010) proposed a similar approach for the multivariate linear regression case. These estimators are highly robust and have under general assumptions a joint limiting multinormal distribution. The estimates are easy to compute using fixed-point algorithms. There are however no exact proofs for the convergence of these algorithms. The existence and uniqueness of the solutions also still remain unproven although we believe that they hold under general conditions. To ci…

Forecasting correlated time series with exponential smoothing models

2011

Abstract This paper presents the Bayesian analysis of a general multivariate exponential smoothing model that allows us to forecast time series jointly, subject to correlated random disturbances. The general multivariate model, which can be formulated as a seemingly unrelated regression model, includes the previously studied homogeneous multivariate Holt-Winters’ model as a special case when all of the univariate series share a common structure. MCMC simulation techniques are required in order to approach the non-analytically tractable posterior distribution of the model parameters. The predictive distribution is then estimated using Monte Carlo integration. A Bayesian model selection crite…

L'ancienne abbaye Saint-Bénigne : Regards croisés. Chronique d'une exposition. Rapport de stage IUT Information-Communication, Université de Bourgogne

1995

Sous la direction de Mme M. Jannet; 2 t. 20 p. et n. p.

Part of speech tagging with Naïve Bayes methods

2014

Hidden Mediterranean diversity: Assessing species taxa by molecular phylogeny within the opilionid family Trogulidae (Arachnida, Opiliones)

2009

This is the first comprehensive study to evaluate the relationships between the western palearctic harvestman families Dicranolasmatidae, Trogulidae and Nemastomatidae with focus on the phylogeny and systematics of Trogulidae, using combined sequence data of the nuclear 28S rRNA and the mitochondrial cytochrome b gene. Bayesian analysis and Maximum parsimony do not reliably resolve Dicranolasma as distinct family but place it on a similar phylogenetic level as several lineages of Trogulidae. Nemastomatidae and Trogulidae turned out to be monophyletic, as did genera Anelasmocephalus and Trogulus within the Trogulidae. The genera Calathocratus, Platybessobius and Trogulocratus each appeared p…

Respiratory proteins in Sipunculus nudus--implications for phylogeny and evolution of the hemerythrin family.

2009

Three major classes of respiratory proteins are known, hemoglobin, molluscan and arthropod hemocyanin, and hemerythrin (Hr). Similar to hemoglobin, respiratory Hr is packed into erythrocytes floating in the coelomic fluid and is only known from sipunculids, brachiopods, and priapulids. Owing to this scattered distribution, the presence of Hr is generally assumed to be the plesiomorphic condition without phylogenetic importance. By sequencing 2000 Expressed Sequence Tags (ESTs) from Sipunculus nudus, we found 75 Hr-coding ESTs assembled to 20 cDNA contigs classified as four distinct Hr isoforms: three polymeric Hrs (subunit A, A', and B) and the monomeric myo-hemerythrin (myoHr). Phylogeneti…

Analysing the mediating role of a network: a Bayesian latent space approach

2020

The use of network analysis for the investigation of social structures has recently seen a rise, due both to the high availability of data and to the numerous insights it can provide into different fields. Most analyses focus on the topological characteristics of networks and the estimation of relationships between the nodes. We adopt a different point of view, by considering the whole network as a random variable conveying the effect of an exposure on a response. This point of view represents a classical mediation setting, where the interest lies in the estimation of the indirect effect, that is, the effect propagated through the mediating variable. We introduce a latent space model mappin…

A Physiological Approach for Minimizing Dead Reckoning Velocity Readings Drifts

2018

The evolution of the geo-positioning methods made Dead Reckoning (DR) one of the most important concern due to its performance in indoor pedestrian localization systems. This paper focuses on implementing an approach that relies on physiological parameters to minimize additive velocity error due to noise in pedestrian DR system.

Emergence and Phylodynamics of Citrus tristeza virus in Sicily, Italy

2013

Citrus tristeza virus (CTV) outbreaks were detected in Sicily island, Italy for the first time in 2002. To gain insight into the evolutionary forces driving the emergence and phylogeography of these CTV populations, we determined and analyzed the nucleotide sequences of the p20 gene from 108 CTV isolates collected from 2002 to 2009. Bayesian phylogenetic analysis revealed that mild and severe CTV isolates belonging to five different clades (lineages) were introduced in Sicily in 2002. Phylogeographic analysis showed that four lineages co-circulated in the main citrus growing area located in Eastern Sicily. However, only one lineage (composed of mild isolates) spread to distant areas of Sici…