322,985 research outputs found
Correction to: Analysing the determinants of Italian university student mobility pathways, (Genus, (2021), 77, 1, (34), 10.1186/s41118-021-00146-2)
No full textFollowing the publication of the original article (Columbu et al., 2021) we were informed that the authors’ given and family names had unfortunately been interchanged. The author names have been corrected in the author list of this Correction and updated in the original article
Conditional concordance of the signs of the residuals of quantile regressions of multivariate outcomes
No full textMateriaux de construction en epoque romaine et aves les ancuennes carrieres: l’exemple du theatre de Nora (Sardaigne SO, Italie)
No full text
Caratterizzazione fisica e qualificazione geomeccanica dell'ammasso roccioso costituente il fronte di scavo di una miniera di argillite a Sàdali (Sarcidano, Sardegna centro-orientale)
No full textThe acquisition and analysis of the physical and mechanical properties and
geostructural character of the rocks, that constitute the excavation front of a argillite’s
quarry for ceramics near to Sàdali, has allowed the geomechanical characterization of
the dolomitic rocky mass and the argillitic formation below. The front is, at the moment,
potentially unstable, with the collapse of dolomitic rock’s blocks on the squares of the
quarry. Instability has been certainly caused by a lack of basal support that interests
main part of the front extension. The analysis of the dolomitic rocky mass has been faced
applying the Classification of Bieniawski, in way to establish its geomechanical quality.
The optimal solution to put in safety the front is the restoration of the basal support,
through the realization of a terrace and a superficial drain system
Multilevel latent class models for cross-classified categorical data: model definition and estimation through stochastic EM
No full textWe present an extension of the multilevel latent class model for dealing with multilevel cross-classified categorical data. Cross-classified data structures arise when observations are simultaneously nested within two or more groups, for example, children nested within both schools and neighborhoods. More specifically, we propose extending the standard hierarchical latent class model, which contains mixture components at two levels, say for children and schools, by including a separate set of mixture components for each of the higher-level crossed classifications, say for schools and neighborhoods. Because of the complex dependency structure arising from the cross-classified nature of the data, it is no longer possible to obtain maximum likelihood estimates of the model parameters, for example, using the EM algorithm. As a solution to the estimation problem, we propose an approximate estimation approach using a stochastic version of the EM algorithm. The performance of this approach, which resembles Gibbs sampling, was investigated through a set of simulation studies. Moreover, the application of the new model is illustrated using an Italian dataset on the quality of university experience at degree programme level, with degree programmes nested in both universities and fields of study
A global review of MSC certification: Why fisheries withdraw?
No full textThe Marine Stewardship Council is the leader in seafood ecolabel certification. Despite its high impact in promoting sustainable fishing and securing price premiums, a large proportion of fisheries withdraw from the scheme during or after certification. We, therefore, investigate the factors influencing the likelihood of withdrawal. To achieve this, we analysed publicly available information from 301 fisheries that have embarked on the certification process using survival analysis methods to investigate the withdrawal rate. It was found that the fishing gear used, and geographical location were the principal factors affecting the likelihood of withdrawal and that the risk of withdrawal is greatest during the full-assessment process and the first five years of certification. Our study also reviews the uneven global expansion of MSC ecolabelling by region and identifies factors that influence withdrawal and need to be considered in fisheries entering MSC certification
Properties of given and detected unbounded solutions to a class of chemotaxis models
No full textThis paper deals with unbounded solutions to a class of chemotaxis systems.
In particular, for a rather general attraction-repulsion model, with nonlinear
productions, diffusion, sensitivities and logistic term, we detect Lebesgue
spaces where given unbounded solutions blow-up also in the corresponding norms
of those spaces; subsequently, estimates for the blow-up time are established.
Finally, for a simplified version of the model, some blow-up criteria are
proved
Comportamenti criminosi e fattori di rischio: un’applicazione del modello del triplo rischio delittuoso in un campione di studenti in Italia
No full textThis paper focuses on youth deviance and delinquency insofar as it tries to understand some key components of juvenile
criminal risk. To this end, the IRIS-J inventory (Individual and Social Risk Factors Inventory for Youth) was used with a
sample of high school students from two Italian contexts: the Nuorese (in the central area of Sardinia) and two cities of
Emilia Romagna (Forlì and Casalecchio di Reno). This instrument allows to assess criminal behavior from the perspective
of the Triple Risk Model for Crime, which considers three sources of criminogenic factors: personal risk factors, lack of
prosocial support, and the exposure of individuals to criminal opportunities.
The results show that the assessed students generally carry out mild antisocial behaviors, such as illegally downloading music
and movies or using public transport without paying the ticket. Only a small percentage of respondents are incline to committing serious or violent crimes (such as selling drugs, injuries and assaults or robberies). Concerning risk factors, some
personality traits (e.g. impulsivity), social factors (e.g. school dissatisfaction) and exposure of adolescents to criminal opportunities appear as influential elements for deviant behavior. Statistical significant differences in antisocial behavior were not
in general observed (with the exception of thefts) between young people from the two areas where the research was carried
out
Interpreting the outcomes of research assessments: A geometrical approach
No full textResearch evaluations and comparison of the assessments of academic institutions (scientific areas, departments, universities etc.) are among the major issues in recent years in higher education systems. One method, followed by some national evaluation agencies, is to assess the research quality by the evaluation of a limited number of publications in a way that each publication is rated among n classes. This method produces, for each institution, a distribution of the publications in the n classes. In this paper we introduce a natural geometric way to compare these assessments by introducing an ad hoc distance from the performance of an institution to the best possible achievable assessment. Moreover, to avoid the methodological error of comparing non-homogeneous institutions, we introduce a geometric score based on such a distance. The latter represents the probability that an ideal institution, with the same configuration as the one under evaluation, performs worst. We apply our method, based on the geometric score, to rank, in two specific scientific areas, the Italian universities using the results of the research evaluation VQR 2011–2014
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