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141.
A comprehensive approach for imposing both row and column constraints on multivariate discrete data is proposed that may be called generalized constrained multiple correspondence analysis (GCMCA). In this method each set of discrete data is first decomposed into several submatrices according to its row and column constraints, and then multiple correspondence analysis (MCA) is applied to the decomposed submatrices to explore relationships among them. This method subsumes existing constrained and unconstrained MCA methods as special cases and also generalizes various kinds of linearly constrained correspondence analysis methods. An example is given to illustrate the proposed method.Heungsun Hwang is now at Claes Fornell International Group. The work reported in this paper was supported by Grant A6394 from the Natural Sciences and Engineering Research Council of Canada to the second author.  相似文献   
142.
When there are order constraints among the parameters of a binary, multinomial processing tree (MPT) model, methods have been developed for reparameterizing the constrained MPT into an equivalent unconstrained MPT. This note provides a theorem that is useful in computing bounds on the estimator variances for the parameters of the constrained model in terms of estimator variances of the parameters of the unconstrained model. In particular, we show that if X and Y are random variables taking values in [0,1], then Var[XY]?2(Var[X]+Var[Y]).  相似文献   
143.
Pictorial space can be conceptualized as aggregate space (where figures compete for limited available space) or as axial space (where space is infinite and exists independently of figures). That these two kinds of space concepts follow a developmental sequence was tested by investigating size regulation mechanisms in 7- to 12-year-old children's figure drawings. An earlier longitudinal study had shown that the more figures were drawn and the more complex the spatial axes system, the smaller the figures. Two studies confirmed that object-driven size reduction was the size regulation mechanism in younger children, whereas axes-driven size reduction was the only factor regulating figure size in 12-year-old children. Size reduction occurred in a gradual fashion in younger children, whereas size reduction was more pronounced in crossed axes systems in older children. In addition, 7-year-old children showed a dynamic and fluid interaction between internal and external task demands for size regulation.  相似文献   
144.
Previous research has found cross-national variations in the association between search for meaning in life (SMIL) and well-being (i.e. SMIL–WB link). This study extended and tested a “self-improvement hypothesis” that accounts for such cross-national variations based on an international database—the sixth wave of World Values Survey. SMIL represents a self-improvement effort which is more demanded in contexts with stronger external constraints. Thus, we expected a stronger positive SMIL–WB link in such contexts. A series of multilevel analyses was used to verify this hypothesis. The results showed that the SMIL–WB link varied across different societies, with well-being indexed by happiness, life satisfaction and subjective health. Moreover, external constraints from cultural, social-institutional, economic and ecological contexts (collectivism, peace threats, economic scarcity and environmental threats) moderated the SMIL–WB links. We thus call for advancing SMIL theory by considering person–context interaction.  相似文献   
145.
Contemporary models for athlete development and performance preparation in sport have advocated a role re-conceptualisation for coaches grounded as learning environment designers. Within this re-conceptualisation, expert practitioners are encouraged to draw upon their experiential knowledge to design representative and meaningful learning activities that place the performer-environment interaction at its core. However, we propose that, currently, a critical source of experiential knowledge is often overlooked within the process of learning design – that of performers. Specifically, practitioner-performer interactions could enrich the design of learning environments by promoting the utilisation of soliciting affordances and encouraging the psychological engagement of performers. This paper introduces the concept of representative co-design – a notion which builds on existing research by framing how the insights and experiences of performers can be negotiated within the design of practice tasks that seek to faithfully simulate interacting constraints of competition to enrich learning environments. We frame the notion of representative co-design, and contend its importance within more contemporary athlete development and performance preparation models, at two levels: (i) that of enriching physical education curricula to develop thought provoking, ‘intelligent’ child/adolescent learners, and (ii) that of enriching contemporary athlete preparation models in high-performance sport to enhance learning and engagement, and to develop ‘next generation’ coaches within current athletes. To bring this conceptualisation to life, we present two exemplars demonstrating the notion of representative co-design, while concurrently highlighting areas for future research.  相似文献   
146.
Chronic and acute stress may have a detrimental effect on children's physical activity. Research on stress as a predictor of children's physical activity has mostly focused on stress between children, rather than how children's within-day variation in stress may predict physical activity. The current study assessed the within- and between-effects of stress on subsequent physical activity in three different time windows using ecological momentary assessment (EMA) and accelerometry. Children (N = 190; MBaseline Age = 10.1 ± 0.9, 53% female, 56% self-identified Hispanic/Latino) completed six semi-annual assessment bursts across three years. During each burst, participants responded to up to seven (weekend) or three (weekday) randomly prompted EMA surveys on smartphones for seven days and wore a waist-worn accelerometer. Multi-level structural equation modeling examined within- and between-subjects effects of stress as a predictor of children's subsequent moderate-to-vigorous physical activity (MVPA) in the 15, 30, and 60 min following the EMA prompt. Latent variables were created for within- and between-subjects stress were comprised of three EMA stress items. Higher than average levels of stress (within-subjects) significantly predicted lower MVPA in the subsequent 15, 30 and 60 min (ps < .05). Between-subjects stress was not significantly associated with subsequent MVPA (ps > .05). Results indicate that elevated momentary stress predicts less subsequent MVPA. These findings suggest that within-day fluctuations in stress may be a barrier for children engaging in physical activity. Childhood physical activity promotion and interventions should consider the role of children's stress, aim to reduce the stress children experience throughout the day, and incorporate stress coping strategies.  相似文献   
147.
The aim was to examine behavioural variability within and between individuals, especially in a swimming task, to explore how swimmers with various specialty (competitive short distance swimming vs. triathlon) adapt to repetitive events of sub-maximal intensity, controlled in speed but of various distances. Five swimmers and five triathletes randomly performed three variants (with steps of 200, 300 and 400 m distances) of a front crawl incremental step test until exhaustion. Multi-camera system was used to collect and analyse eight kinematical and swimming efficiency parameters. Analysis of variance showed significant differences between swimmers and triathletes, with significant individual effect. Cluster analysis put these parameters together to investigate whether each individual used the same pattern(s) and one or several patterns to achieve the task goal. Results exhibited ten patterns for the whole population, with only two behavioural patterns shared between swimmers and triathletes. Swimmers tended to use higher hand velocity and index of coordination than triathletes. Mono-stability occurred in swimmers whatever the task constraint showing high stability, while triathletes revealed bi-stability because they switched to another pattern at mid-distance of the task. Finally, our analysis helped to explain and understand effect of specialty and more broadly individual adaptation to task constraint.  相似文献   
148.
We examined whether anticipation is underpinned by perceiving structured patterns or postural cues and whether the relative importance of these processes varied as a function of task constraints. Skilled and less-skilled soccer players completed anticipation paradigms in video-film and point light display (PLD) format. Skilled players anticipated more accurately regardless of display condition, indicating that both perception of structured patterns between players and postural cues contribute to anticipation. However, the Skill × Display interaction showed skilled players’ advantage was enhanced in the video-film condition, suggesting that they make better use of postural cues when available during anticipation. We also examined anticipation as a function of proximity to the ball. When participants were near the ball, anticipation was more accurate for video-film than PLD clips, whereas when the ball was far away there was no difference between viewing conditions. Perceiving advance postural cues appears more important than structured patterns when the ball is closer to the observer, whereas the reverse is true when the ball is far away. Various perceptual-cognitive skills contribute to anticipation with the relative importance of perceiving structured patterns and advance postural cues being determined by task constraints and the availability of perceptual information.  相似文献   
149.
150.
Worry is crucial in the development and maintenance of anxiety disorders and has been associated with several other adverse health outcomes. Yet, little is known about the frequency and perseveration of worry in daily life, and its predictability by widely used trait questionnaires. In this study 432 students completed the Penn State Worry Questionnaire (PSWQ), the Worry Domains Questionnaire (WDQ) and the State-Trait Anxiety Inventory-Trait version (STAI-T) and kept a log of worry frequency and duration during six consecutive days and nights. The results showed that worry is a very common phenomenon that is predicted by the two trait worry questionnaires, independent of trait anxiety. The often clinically utilized PSWQ predicted worry duration better than the WDQ, and exclusively predicted night-time worry and several other indices of perseverative and potentially pathogenic worry. Although this study provides some support for the predictive validity of the PSWQ and the WDQ, these questionnaires did not account for the larger part of variance in daily worry. Future studies of worry and its associated perseverative processes should consider using momentary assessments.  相似文献   
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