On exact strong laws of large numbers for ratios of random variables and their applications

Abstract

We study the almost sure convergence of weighted sums of ratios of independent random variables satisfying some general, mild conditions. The obtained results are applied to exact laws for order statistics. An exact law for independent random variables which are nonidentically distributed is also proved and applied to ratios of adjacent order statistics for a sample of uniformly distributed random variables.     

The Role of Leadership in the Management of Conflict and Knowledge Sharing in the Research Groups of a Spanish Public University

Public Organization Review - This paper analyses how academics perceive their group leaders’ behaviour in managing the scientific activities of their research group and, particularly, how the...     

WhiteSpace,Brown Place: Racialized Experiences Accessing Public Space in an Arkansas Immigrant Community*

This article examines the experiences of Latinos in Northwest Arkansas as they partake in community life within the Jones Center as a public setting traditionally dominated by legal and cultural practices intended to maintain white outlooks. We develop a conceptual model of race and space to theoretically frame how the implementation of an entrance fee system in this community setting shapes public space access into a restrictive racialized place. Drawing on ethnography and visual data gathered between fall 2014 and spring 2015, we found that the administration of the Jones Center made no effort to foster a more inclusive environment, creating a social atmosphere wherein participants construct the place as a whitespace. Whereas some challenged the exclusionary dimensions of symbolic white markers through spatial practices of resistance, others remained in what we call racialized subspaces. We argue that this form of restricting access aims to systematically, yet subtly preclude access to specific areas of the setting—i.e., swimming pool and ice rink. Nevertheless, participants in this study also demonstrate how community resiliency enables them to use “non-restricted” areas within the whitespace as mechanisms to disrupt the meaning of white markers symbolically embedded in areas where access cannot be negotiated by local Latinos.     

Frailty in the Old Age as a Direct Marker of Quality of Life and Health: Gender Differences

Social Indicators Research - Aging of the population emphasizes the need for research on aging-related problems, among which frailty is a key element because of its clinical as well as social...     

The impact of affectivity on the behaviour of Portuguese adolescents / El impacto de la afectividad en la conducta de los adolescentes portugueses

The theoretical literature about affectivity shows its influence over positive and negative behaviour. This study analyses the impact of affectivity on the behaviour of Portuguese adolescents, as this knowledge is considered relevant to promoting skills and decreasing risky behaviours in adolescents. A total of 696 students (M = 15.22 years old; SD = 1.4) participated in this study by responding to the PANAS-N (Positive and Negative Affect Schedule) and SDQ (Strengths and Difficulties Questionnaire). The former measures the level of affect while the latter measures prosocial behaviours, emotional symptoms and behavioural problems. The results showed that positive affect positively influences prosocial behaviour. Emotional symptoms and behaviour problems are negatively affected by positive affect, and positive symptoms and behaviours by negative affect. Moreover, boys had higher scores on behaviour problems, while girls had higher scores in prosocial behaviour and emotional symptoms. For these reasons, affectivity should be considered in programmes to reduce behaviour problems and emotional symptoms.     

Some results on the injective chromatic number of?graphs

A k-coloring of a graph G=(V,E) is a mapping c:V??{1,2,??,k}. The coloring c is injective if, for every vertex v??V, all the neighbors of v are assigned with distinct colors. The injective chromatic number ?? _i (G) of G is the smallest k such that G has an injective k-coloring. In this paper, we prove that every K ₄-minor free graph G with maximum degree ????1 has $\chi_{i}(G)\le \lceil \frac{3}{2}\Delta\rceil$ . Moreover, some related results and open problems are given.     

Statistical analysis of controlled calibration model with replicates

In this work, we generalize the controlled calibration model by assuming replication on both variables. Likelihood-based methodology is used to estimate the model parameters and the Fisher information matrix is used to construct confidence intervals for the unknown value of the regressor variable. Further, we study the local influence diagnostic method which is based on the conditional expectation of the complete-data log-likelihood function related to the EM algorithm. Some useful perturbation schemes are discussed. A simulation study is carried out to assess the effect of the measurement error on the estimation of the parameter of interest. This new approach is illustrated with a real data set.     

Estimation of the angular density in bivariate generalized Pareto models

We investigate a method to estimate the angular density non-parametrically in bivariate generalized Pareto models. The angular density can be used as a visual tool to gain a first insight into the tail-dependence structure of given data. We derive a representation of the angular density by means of the Pickands density and use it to construct our estimator. The estimator is asymptotically normal under certain regularity conditions. We also test it with simulated data and give an application to a real hydrological data set. Finally, we show that our estimator cannot be transferred directly to higher dimensions.