Search results for " statistics"
showing 10 items of 1891 documents
La situation de l’artisanat verrier à Augustodunum dans le contexte des découvertes effectuées en Gaule
2007
Il est rappelé d’abord que les cartes de répartition des ateliers de verriers en Gaule, aux premiers siècles de notre ère, écartent de nombreux sites de transformation de verre brut importé du Proche-Orient, au motif qu’on n’y a pas retrouvé de déchets exploitables d’un point de vue typologique. Mais les traces d’activités verrières de cette époque semblent bien plus nombreuses que ne le montrent ces cartes, à l’instar de ce qu’on observe à Autun.Malgré le caractère bien incomplet de nos connaissances sur la répartition des ateliers de verriers anciens de Gaule romaine, cette répartition constitue dès à présent un solide argument en faveur de la prépondérance pour le verre d’un commerce de …
A method based on texture feature and edge detection for people counting in a crowded area
2019
We propose a population counting method for feature fusion and edge detection.The image is extracted from multiple information sources to estimate the count by image feature extraction and texture feature analysis, as well as for crowd head edge detection. We count people in high-density still images.For example, in the city bus station, subway. Our method uses a still image taken by the camera to estimate the count in the crowd density image, using multiple sources of information, namely: HOG, LBP, CANNY, these sources provides separate estimates of the number of counts and other statistical measures, through the support vector Machine SVM, classification, and regression analysis to obtain…
A recap on Linear Mixed Models and their hat-matrices
2017
This working paper has a twofold goal. On one hand, it provides a recap of Linear Mixed Models (LMMs): far from trying to be exhaustive, this first part of the working paper focusses on the derivation of theoretical results on estimation of LMMs that are scattered in the literature or whose mathematical derivation is sometimes missing or too quickly sketched. On the other hand, it discusses various definitions that are available in the literature for the hat-matrix of Linear Mixed Models, showing their limitations and proving their equivalence.
Modelling the presence of disease under spatial misalignment using Bayesian latent Gaussian models.
2015
Modelling patterns of the spatial incidence of diseases using local environmental factors has been a growing problem in the last few years. Geostatistical models have become popular lately because they allow estimating and predicting the underlying disease risk and relating it with possible risk factors. Our approach to these models is based on the fact that the presence/absence of a disease can be expressed with a hierarchical Bayesian spatial model that incorporates the information provided by the geographical and environmental characteristics of the region of interest. Nevertheless, our main interest here is to tackle the misalignment problem arising when information about possible covar…
Social Support and Resilience as Predictors of Prosocial Behaviors before and during COVID-19
2022
The objective of this research was to analyze the relationship between social support and resilience with prosocial behavior before and during the confinement caused by COVID-19. Materials and Methods: The participants were divided into a confined group (228 women and 84 men) and an unconfined group (153 women and 105 men), all of whom were university students. Instruments were applied to measure the variables proposed. Results: Social support predicted 24.4% of the variance in prosocial behavior among women and 12% among men in the confined group; no evidence of this relationship was found in the unconfined groups. Resilience predicted 7% of the variance in prosocial behavior among confine…
Reporting heterogeneity in health: an extended latent class approach
2012
This article explores how individual socio-economic characteristics affect unobserved heterogeneity in self-reporting behaviour and health production using a multivariate finite mixture model. Results show a positive relationship between objective and subjective observable health indicators and true health and support the existence of self-reporting bias related to socio-economic characteristics and individual life styles.
Do different models induce changes in mortality indicators? That is a key question for extending the Lee-Carter model
2021
[EN] The parametric model introduced by Lee and Carter in 1992 for modeling mortality rates in the USA was a seminal development in forecasting life expectancies and has been widely used since then. Different extensions of this model, using different hypotheses about the data, constraints on the parameters, and appropriate methods have led to improvements in the model's fit to historical data and the model's forecasting of the future. This paper's main objective is to evaluate if differences between models are reflected in different mortality indicators' forecasts. To this end, nine sets of indicator predictions were generated by crossing three models and three block-bootstrap samples with …
Bayesian correlated models for assessing the prevalence of viruses in organic and non-organic agroecosystems
2017
Cultivation of horticultural species under organic management has increased in importance in recent years. However, the sustainability of this new production method needs to be supported by scientific research, especially in the field of virology. We studied the prevalence of three important virus diseases in agroecosystems with regard to its management system: organic versus non-organic, with and without greenhouse. Prevalence was assessed by means of a Bayesian correlated binary model which connects the risk of infection of each virus within the same plot and was defined in terms of a logit generalized linear mixed model (GLMM). Model robustness was checked through a sensitivity analysis …
Testing for goodness rather than lack of fit of an X–chromosomal SNP to the Hardy-Weinberg model
2019
The problem of checking the genotype distribution obtained for some diallelic marker for compatibility with the Hardy-Weinberg equilibrium (HWE) condition arises also for loci on the X chromosome. The possible genotypes depend on the sex of the individual in this case: for females, the genotype distribution is trinomial, as in the case of an autosomal locus, whereas a binomial proportion is observed for males. Like in genetic association studies with autosomal SNPs, interest is typically in establishing approximate compatibility of the observed genotype frequencies with HWE. This requires to replace traditional methods tailored for detecting lack of fit to the model with an equivalence test…
Empirical Likelihood-Based ANOVA for Trimmed Means
2016
In this paper, we introduce an alternative to Yuen’s test for the comparison of several population trimmed means. This nonparametric ANOVA type test is based on the empirical likelihood (EL) approach and extends the results for one population trimmed mean from Qin and Tsao (2002). The results of our simulation study indicate that for skewed distributions, with and without variance heterogeneity, Yuen’s test performs better than the new EL ANOVA test for trimmed means with respect to control over the probability of a type I error. This finding is in contrast with our simulation results for the comparison of means, where the EL ANOVA test for means performs better than Welch’s heteroscedastic…