The modified slash Lindley–Weibull distribution with applications to nutrition data

This work presents an extension of the slash Lindley–Weibull distribution, of which it can be considered a modification. The new family is obtained by using the quotient of two independent random variables: a two-parameter Lindley–Weibull distribution divided by a power of the exponential distribution with parameter equal to 2. We present the pdf and cdf of the new distribution, analyzing their risk functions. Some statistical properties are studied and the moments and coefficients of asymmetry and kurtosis are shown. The parameter estimation problem is carried out by the maximum likelihood method. The method is assessed by a Monte Carlo simulation study. We use nutrition data, which are characterized by high kurtosis, to illustrate the usefulness of the proposed model.     

Normes,théorie des jeux et pratiques participatives: le poids réel des travailleurs dans les économies libérales

Les auteurs analysent l'effet de la directive européenne relative à l'information et à la consultation des travailleurs sur les pratiques participatives en entreprise au Royaume‐Uni et en Irlande. Dans une analyse conceptuelle et empirique, qui fait appel à la théorie des jeux, ils formulent trois hypothèses explicatives, qu'ils cherchent à vérifier avec des données qualitatives recueillies auprès de seize entreprises. La démonstration permet de comprendre pourquoi la coopération, gage de gains mutuels, n'est pas la solution qui l'emporte dans les pays examinés, et elle nous en dit un peu plus sur l'effet des normes sur la gestion participative dans les économies de marché libérales.     

Asymptotic Bias in Parameter Estimation of AR-Processes Using Recursive Least Squares with Exponential Forgetting

The recursive least squares technique is often extended with exponential forgetting as a tool for parameter estimation in time-varying systems. The distribution of the resulting parameter estimates is, however, unknown when the forgetting factor is less than one. In this paper an approximative expression for bias of the recursively obtained parameter estimates in a time-invariant AR( n_a ) process with arbitrary noise is given, showing that the bias is non-zero and giving bounds on the approximation errors. Simulations confirm the approximation expressions.     

Psychosocial Well-Being of Young People Who Participated in a Support Group Following the Loss of a Parent to Cancer

Despite the evidence of unmet support needs among young people who have lost a parent to cancer, only a few support group initiatives have been reported. This observational prospective study explored the psychosocial well-being of young people who participated in support groups at a Swedish specialist palliative care setting. On three occasions, 29 participants, aged 16–28 years, answered questionnaires covering characteristics of the participants, circumstances of the losses, psychosocial well-being of the young people, and their own assessment of the support groups. The support groups attracted mostly young women who were often unprepared for the loss. The living arrangements differed between younger and older participants; however, the loss-related variables did not differ. Significant positive changes were found regarding a sense of meaning in their future life and life satisfaction. The helpfulness of the group was assessed as high/very high and the group brought a valuable fellowship with others in a similar situation. Universality and beneficial interactions were reported and strengthened psychosocial well-being developed over time. This change, according to the young people themselves, may be attributed to the group support. The findings are useful for planning interventions to support young people in bereavement in order to enhance their psychosocial well-being.     

Longitudinal Prediction of Mid‐Adolescent Psychosocial Outcomes From Early Adolescent Family Help Seeking and Family Support

This study examined whether family help seeking and family support represented the same or distinct constructs and prospective associations between emergent constructs and psychosocial outcomes. Data were from 1,713 school‐based adolescents participating in a randomized controlled trial, in Victoria, Australia. Family help seeking emerged as a single factor, distinct from family support, and was prospectively associated with improved psychosocial outcomes. Father closeness predicted lower depressive symptoms. Family help seeking predicted higher help seeking for peers. Interactions between family help seeking and family support on psychosocial outcomes were not apparent. Findings highlight the importance of examining family help seeking and family support separately in future studies of adolescents' help‐seeking behavior.     

A Parametric Estimation Procedure for Relapse Time Distributions

In a relapse clinical trial patients who have recovered from some recurrent disease (e.g.,ulcer or cancer) are examined at a number of predetermined times. A relapse can be detected either at one of these planned inspections or at a spontaneous visit initiated by the patient because of symptoms. In the first case the observations of the time to relapse, X, is interval-censored by two predetermined time-points. In the second case the upper endpoint of the interval is an observation of the time to symptoms,Y . To model the progression of the disease we use a partially observable Markov process. This approach results in a bivariate phase-type distribution for the joint distribution of (X,Y). It is a flexible model which contains several natural distributions for X, and allows the conditional distributions of the marginals to smoothly depend on each other. To estimate the distributions involved we develop an EM-algorithm. The estimation procedure is evaluated and compared with a non-parametric method in a couple of examples based on simulated data.     

Living Close to a Person With Cancer: A Review of the International Literature and Implications for Social Work Practice

To help family caregivers (FCs), social workers need to understand the complexity of FC’s experiences and challenges. For this systematic review, several relevant, multidisciplinary electronic databases were searched. Of 1,643 titles identified, 108 articles met the inclusion criteria and are included in this review. Various experiences, symptoms, and burden related to caregiving responsibilities are described and discussed. The understanding evolving from this study about the FC’s own health risk, caregiver burden, and experiences over time can enhance a social worker’s awareness of an FC’s challenging situation and the potential impact this has on the FC’s ability to provide care to the patient.     

At risk of exclusion? Degrees of ICT access and literacy among senior citizens

Drawing on data derived from a nationwide postal survey (n?=?1264) with a simple random sample of Swedes between ages 65 and 85 (response rate: 63%), the article analyses the general patterns of: (a) degrees of information and communication (ICT) access and (b) ICT-literacy among Swedish senior citizens. The overall patterns of access and literacy are analysed in light of senior citizens’ assets – conceptualized as material, discursive and social resources – and their age and gender. The analysis reveals a positive correlation between levels of material (e.g., income), discursive (e.g., English skills) and social (e.g., social networks) resources and access to ICT. With greater resources, the average number of devices increases. The analysis also reveals a positive correlation between discursive and social resources and ICT-literacy. Gender has no bearing on access to devices, but might have some effect on ICT-literacy. The correlation between age, access and literacy is negative. With increasing age, both access and literacy decreases. In this respect, the study reveals a generational effect. However, since all three resources tend to decrease over the life cycle, the results are also discussed in terms of an age effect. These data and our analyses are contextualized by a critical discussion that reflects on the implications of these general patterns: What do they mean for senior citizens’ abilities to be included and participate in a continuously digitalizing society?     

Estimating population characteristics by incorporating prior values in stratified random sampling/ranked set sampling

In this paper, we discuss the estimation of population characteristics using stratified random sampling in an infinite population framework, including ranked set sampling as a special case. The use of prior values is considered and the underlying distribution is assumed to be unknown. The estimator considered in each stratum is the weighted mean of the U-statistic and prior value. The optimum weight is obtained by minimizing the mean squared error of the estimator of the population characteristics, but it contains unknown parameters and those parameters are replaced with their estimates. Simulation results show the gains in efficiency of the proposed estimator, yielding gains of at least 1.2 times larger than the usual unbiased estimator under certain condition specified in the text. Guidelines for the usage of the proposed estimator are shown and an application to a real data set is provided.     

OBTAINING AND PARAMETERIZING MULTIPERIOD PORTFOLIOS WITH DESIRABLE CHARACTERISTICS UNDER LOGNORMAL RETURNS

The expected geometric mean has been shown to be a valuable criterion in ranking portfolios of assets. For example, under certain conditions the maximum expected geometric-mean portfolio minimizes the expected time to amass a fixed level of wealth as wealth becomes “large.” This paper develops a simple algorithm for obtaining such portfolios when portfolio returns are assumed to be lognormally distributed. The risk-return characteristics of portfolios are derived and illustrated using data from a subset of stocks found on the New York Stock Exchange.