Augmenting lehmann alternatives for improving asymptotic efficiency of rank tests

Locally most powerful tests for augmented simple Lehmann alternatives are obtained. These tests turn out to be linearcombinations of the Savage and Mann-Whitney-Wilcoxon test criteria. We study their performance in terms of the asymptotic efficiency relative to their parametric competitors against location and scale alternatives. For small sample sizes, critical points of a couple of test procedures are given.     

Model Selection When a Key Parameter is Constrained to be in an Interval

This article considers model selection procedures based on choosing the model with the largest maximized log-likelihood minus a penalty, when key parameters are restricted to be in a closed interval. Its main emphasis is how these penalties might be chosen in small samples to give good properties of the resultant procedure. We illustrate two model selection problems in the context of Box–Cox transformations and their application to the linear regression model. Simulation results for both problems indicate that the new procedure clearly dominates existing procedures in terms of having higher probabilities of correctly selecting the true model.     

Statistical Analysis for the Inverse Trinomial Distribution

This article considers parameter estimation, goodness of fit, likelihood ratio and score tests, and model selection by Akaike information criterion for the inverse trinomial (IT) distribution, a classical one-dimensional random walk distribution. The IT distribution has a cubic variance function of the mean and is a generalization of the negative binomial distribution. Basic distributional properties and expressions for the probability mass function, recurrence formula, moments, and score functions are also presented.     

Toward a carnivalesque analysis of hacking: A qualitative study of Iranian hackers

This study sought to analyze Iranian hackers’ lived experiences based on the concept of the carnival of crime in cultural criminology. Fifty-four in-depth semi-structured interviews were conducted with young hackers. Moreover, their behaviors were observed along with those of other hackers. The data were coded through a thematic analysis using MAXQDA software. The study's findings indicated that cyberspace had created a carnivalesque utopia that allowed the young Iranian hackers to experience the pleasure of crime. By trespassing the rational frameworks of the modern world and altering the trends of knowledge creation as a means for subjugation, Iranian hackers contribute to the meaning-construction policies of those in power and challenge authoritarian aesthetics by invading their electronic domain. It was also found that the carnivalesque lives of hackers provided them with a variety of opportunities for disrupting the rhythms of production and creating an underground carnivalesque economy based on their level of knowledge.     

Behavioural problems of adolescents in secure residential youth care: Gender differences and risk factors

Adolescents in secure residential care mostly suffer from serious behavioural problems, often accompanied by trauma and adverse family circumstances. This paper presents findings of a comparison of behavioural problems and risk factors of 255 boys and girls (aged 12 to 18 years) in secure residential care in the Netherlands and their association with behavioural problems. A cross-sectional design and standardized questionnaires were used to measure behavioural problems and individual and familial risk factors. By using independent-sample t tests, the severity of these factors in boys and girls was compared, and by using structural equation modelling (SEM), associations between these factors and behavioural problems were investigated. The findings of the study show that post-traumatic stress disorder (PTSD) symptoms, maladaptive emotion regulation, impaired perceived competence and internalizing behavioural problems were more severe in girls than in boys. Boys experienced more severe externalizing behavioural problems and more family problems than girls. Maladaptive emotion regulation, PTSD symptoms, perceived competence and parenting problems were related to behavioural problems. The results indicate that treatment for girls should address PTSD symptoms, perceived competence and maladaptive emotion regulation and that extra attention for family problems in the treatment of boys is warranted.     

SCHEDULING HYBRID FLOWSHOPS IN PRINTED CIRCUIT BOARD ASSEMBLY LINES*

We treat a three‐stage hybrid flowshop for the production of printed circuit boards (PCB), suggested to us by a real‐life production situation. The problem is to determine a schedule that minimizes the makespan for a given demand profile over a finite planning horizon. We propose a global procedure that utilizes genetic algorithms and three subproblems. The performance of the procedure is evaluated via experimentation over thousands of problem realizations that are randomly generated. The experimental results show the efficiency of the global procedure and provides qualitative answers to the allocation of machines to the various stages.     

Early social referencing predicts object mastery motivation in infancy: Social antecedents of object mastery motivation

The researchers sought to understand the typical development of social referencing and object mastery motivation in infancy and to determine the relationship between social referencing and object mastery behaviors in infants from 7 to 22 months of age. The study included 36 infants who were followed as part of a longitudinal study of at-risk infants but were not determined to need care in the neonatal intesive care unit at birth. Both mastery behaviors of persistence and success showed a statistically significant effect of age, while social behaviors remained stable from 7 to 22 months. Social behaviors at 7 and 10 months were correlated with persistence at 22 months and success at 16 to 22 months demonstrating that early social referencing predicts object mastery behaviors in later infancy. Further research should determine if this trend extends to early childhood.