Transformed density rejection with inflection points

The acceptance-rejection algorithm is often used to sample from non-standard distributions. For this algorithm to be efficient, however, the user has to create a hat function that majorizes and closely matches the density of the distribution to be sampled from. There are many methods for automatically creating such hat functions, but these methods require that the user transforms the density so that she knows the exact location of the transformed density’s inflection points. In this paper, we propose an acceptance-rejection algorithm which obviates this need and can thus be used to sample from a larger class of distributions.     

On the reaction time of moving sum detectors

In this paper, we quantify the reaction time of on-line monitoring schemes for changes in the mean based on moving sums. The corresponding sequential test procedure requires a historical sample of size m   as a baseline, while decisions are made based on a window of size h=h(m)$h=h(m)$ containing the h most recent observations. Perhaps surprisingly, the limit distribution (obtained as m tends to infinity) of the associated stopping time crucially depends on the asymptotic relation of these two quantities, posing potential problems in applications. In the empirical part of the paper, we study therefore the finite sample behavior of the monitoring schemes. We provide tables of critical values for the various limit distributions and guidelines for practitioners via a simulation study.     

On Vervaat and Vervaat-error-type processes for partial sums and renewals

We study the asymptotic behaviour of stochastic processes that are generated by sums of partial sums of i.i.d. random variables and their renewals. We conclude that these processes cannot converge weakly to any nondegenerate random element of the space D[0,1]$D[0,1]$. On the other hand, we show that their properly normalized integrals as Vervaat-type stochastic processes converge weakly to a squared Wiener process. Moreover, we also deal with the asymptotic behaviour of the deviations of these processes, the so-called Vervaat-error-type processes.     

Secure attachment and social and personality outcomes: The moderating role of emerging adults’ autobiographical memories of parents

Schema-congruent positive autobiographical memories of past experiences with parents, a legacy of secure attachment, may operate jointly with secure attachment to predict social and personality outcomes. The current study examines the moderating role of emerging adults’ autobiographical memories of parents on the relations between maternal and paternal attachment and self-regulation, personal distress, and pathological narcissism. Undergraduates (N = 156, 66.7% female, 53.2% White, M_age = 19.3) completed a battery of measures assessing secure attachment, self-regulation, personal distress, and pathological narcissism (vulnerable and grandiose). Participants were instructed to recall brief autobiographical memories of experiences with their parental figures. Later, they were asked to name the primary emotion associated with each memory. These emotions were coded as positive, negative, or neutral in valence. For the final analysis, a positive emotion index was constructed by subtracting the number of negative memories from the number of positive memories. Regression models simultaneously examining four outcomes (self-regulation, personal distress, and vulnerable and grandiose narcissism) were examined for both female and male parental figures. Interactions between secure attachment and positive memories were only significant for maternal model outcomes. Secure attachment was positively related to self-regulation, and negatively related to personal distress and vulnerable narcissism, when more relative positive memories were recalled. Taken together, this study provides support for the continued influence of secure attachment on social and personality outcomes in emerging adulthood. Further, this influence of secure attachment appears buttressed by readily accessible positive (relative to negative) memories of female attachment figures.     

Resilience,Moorings and International Student Mobilities – Exploring Biographical Narratives of Social Science Students in the UK

Whilst research into the changing landscape of the UK Higher Education (HE) has produced a burgeoning literature on ‘internationalisation’ and ‘transnational student mobility’ over the past few years, still fairly little is known about international students’ experiences on their way to and through the UK higher and further education. Frequently approaching inter- and transnational education as ‘neutral’ by-products of neoliberal globalisation, elitism and power flows, much HE policy and scholarly debate tend to operate with simplistic classifications of ‘international students’ and therefore fail to account for the multifaceted nature of students’ aspirations, mobilities and life experiences. Drawing on the notion of ‘resilience’ and insights from the ‘new mobilities paradigm’, this paper envisages alternative student mobilities which run parallel or counter to the dominant flows of power, financial and human capital commonly associated with an emerging global knowledge economy. Engaging with ‘resilient’ biographies of social science students studying at three UK HE institutions, the paper challenges narrow student classification regimes and calls for a critical re-evaluation of the relationship between international student mobility and other contemporary forms of migration, displacement and diaspora.     

Serious games in prevention and rehabilitation—a new panacea for elderly people?

Digital games cannot only be used for fun and entertainment. The term “serious games” (SG) denotes digital games serving serious purposes like education, training, advertising, research and health. Recently, a new generation of games has emerged involving whole-body movements. Compared to traditional interventions, these games may help elderly people to improve their health by enhancing physical fitness and coordinative abilities by combining increased motivation, game experience like fun and game flow and training. Serious games, particularly adventure and shooter games, already play an important role in health education, prevention and rehabilitation, e.g. to enhance health-related physical activity, improve sensory–motor coordination, prevent asthma, change nutrition behaviour and alleviate diabetes and prevent smoking or HIV. In this paper, the impact of SG on prevention and rehabilitation is discussed. Three criteria are applied. Beyond effectivity and efficiency, the additional benefits of serious games can be described and explained by different models including social, psychological, physiological and sensory–motor factors. The quality of study serves as a third criterion. Despite first promising results, there are only few high-quality studies. Adequate content, game interfaces, sustainability and appropriate settings are critical factors for the success of SG. In this regard, (sport) science can help to develop and evaluate SG and test appropriate settings that ensure sustainable use of serious games.     

Rule learning transfer across linguistic and visual modalities in 7-month-old infants

Rule learning (RL) refers to infants’ ability to extract high-order, repetition-based rules from a sequence of elements and to generalize them to new items. RL has been demonstrated in both the auditory and the visual modality, but no studies have investigated infants’ transfer of learning across these two modalities, a process that is fundamental for the development of many complex cognitive skills. Using a visual habituation procedure within a cross-modal RL task, we tested 7-month-old infants’ transfer of learning both from speech to vision (auditory-visual—AV—condition) and from vision to speech (visual-auditory—VA—condition). Results showed a transfer of learning in the AV condition, but only for those infants who were able to efficiently extract the rule during the learning (habituation) phase. In contrast, in the VA condition infants provided no evidence of RL. Overall, this study indicates that 7-month-old infants can transfers high-order rules across modalities with an advantage for transferring from speech to vision, and that this ability is constrained by infants’ individual differences in the way they process the to-be-learned rules.