Search results for " statistica"
showing 10 items of 2672 documents
Association between passive tobacco exposure and caries in children and adolescents. A systematic review and meta-analysis.
2017
To examine the available evidence on the association between exposure to tobacco use in the womb and in infancy and the presence of caries in primary and permanent dentition in children and adolescents. A systematic review was conducted through searches in 4 data bases (Pubmed, Scopus, Embase and Web of Science), complemented by hand-searching. Of the 559 articles identified, 400 were duplicates. Finally, 28 articles were included in the qualitative review and 21 in the meta-analysis. Their quality was assessed using the Newcastle-Ottawa scale. The quality was medium in 44% of the articles included and high in 56%. The overall meta-analysis gave a significant odds ratio (OR = 1.53, 95% conf…
La misurazione della performance dei distretti turistici: una proposta
2014
Il presente lavoro si propone di affrontare il tema della valutazione di impatto territoriale dell'esperienza distrettuale.
The territories of tourism: a reflection about the experience of the Tourist Districts (Local Tourism Systems) in Sicily
2013
The tourist district is an important tool for territorial governance of regional tourism. The district is a type of Local System which is characterized by its multidimensionality, as well as the spatial contiguity of traders who belong to it. The territory is a space transformed by social interactions and relations of production: it is therefore the indispensable reference for measuring the impact of tourism. A bottom up approach in the process of identification of the districts is therefore vital. A Balance Score Card-approach is desirable to correctly manage this process. This study is a preliminary analysis derived from direct experience of the Sicilian tourist districts, recently formed…
A statistical model for predicting the inter-annual variability of birch pollen abundance in Northern and North-Eastern Europe
2018
The paper suggests a methodology for predicting next-year seasonal pollen index (SPI, a sum of daily-mean pollen concentrations) over large regions and demonstrates its performance for birch in Northern and North-Eastern Europe. A statistical model is constructed using meteorological, geophysical and biological characteristics of the previous year). A cluster analysis of multi-annual data of European Aeroallergen Network (EAN) revealed several large regions in Europe, where the observed SPI exhibits similar patterns of the multi-annual variability. We built the model for the northern cluster of stations, which covers Finland, Sweden, Baltic States, part of Belarus, and, probably, Russia and…
Hybrid kernel estimates of space-time earthquake occurrence rates using the Etas model
2010
The following steps are suggested for smoothing the occurrence patterns in a clustered space–time process, in particular the data from an earthquake catalogue. First, the original data is fitted by a temporal version of the ETAS model, and the occurrence times are transformed by using the cumulative form of the fitted ETAS model. Then the transformed data (transformed times and original locations) is smoothed by a space–time kernel with bandwidth obtained by optimizing a naive likelihood cross-validation. Finally, the estimated intensity for the original data is obtained by back-transforming the estimated intensity for the transformed data. This technique is used to estimate the intensity f…
Dynamic Gaussian Graphical Models for Modelling Genomic Networks
2014
After sequencing the entire DNA for various organisms, the challenge has become understanding the functional interrelatedness of the genome. Only by understanding the pathways for various complex diseases can we begin to make sense of any type of treatment. Unfortunately, decyphering the genomic network structure is an enormous task. Even with a small number of genes the number of possible networks is very large. This problem becomes even more difficult, when we consider dynamical networks. We consider the problem of estimating a sparse dynamic Gaussian graphical model with \(L_1\) penalized maximum likelihood of structured precision matrix. The structure can consist of specific time dynami…
Bayesian Inference for the Exponential Power Function Parameters
2008
This paper addresses the problem of obtaining the marginal posterior distributions, via Gibbs Sampler, for the parameters of the well-known generalized error distribution called Exponential Power Function (E.P.F.). This density represents a family of unimodal symmetric distributions with shapes varying from leptokurtic to platikurtic.
IL REGISTRO REGIONALE DELLE CRONICITÀ: NUOVI ALGORITMI PER LA VALUTAZIONE DEI PROFILI DI CONSUMI PER CATEGORIE DIAGNOSTICHE IN SICILIA
2013
Introduzione. Conoscere la prevalenza di una malattia cronica è essenziale per una corretta programmazione delle risorse economiche e umane necessarie per l’implementazione delle strategie preventive e terapeutiche. La Base Dati degli Assistibili (BDA), sviluppata nell’ambito del Piano Operativo di Assistenza Tecnica alle Regioni dell’Obiettivo Convergenza (POAT) cui la Regione Sicilia partecipa attivamente, consente dianalizzare in modo integrato le informazioni provenienti dai diversi flussi informativi che la costituiscono. Obiettivi. Costituire un registro regionale delle cronicità in Sicilia, al fine di valutare i profili di consumi per categorie diagnostiche e stimarne i relativi cari…
Nucleation pathway and kinetics of phase-separating active Brownian particles
2016
Suspensions of purely repulsive but self-propelled Brownian particles might undergo phase separation, a phenomenon that strongly resembles the phase separation of passive particles with attractions. Here we employ computer simulations to study the nucleation kinetics and the microscopic pathway active Brownian disks take in two dimensions when quenched from the homogeneous suspension to propulsion speeds beyond the binodal. We find the same qualitative behavior for the nucleation rate as a function of density as for a passive suspension undergoing liquid-vapor separation, suggesting that the scenario of an effective free energy also extends to the kinetics of phase separation. We study the …
Critical end point behaviour in a binary fluid mixture
1997
We consider the liquid-gas phase boundary in a binary fluid mixture near its critical end point. Using general scaling arguments we show that the diameter of the liquid-gas coexistence curve exhibits singular behaviour as the critical end point is approached. This prediction is tested by means of extensive Monte-Carlo simulations of a symmetrical Lennard-Jones binary mixture within the grand canonical ensemble. The simulation results show clear evidence for the proposed singularity, as well as confirming a previously predicted singularity in the coexistence chemical potential [Fisher and Upton, Phys. Rev. Lett. 65, 2402 (1990)]. The results suggest that the observed singularities, particula…