Free-play Behaviors Research Articles

Numerical Analysis of Free Play-Induced Aeroelastic Phenomena: A Numerical Approach With Adaptive Step Size Control

This study presents a detailed numerical analysis of nonlinear aeroelastic behavior in a two degree of freedom (DOF) model, focusing on plunge and pitch motions and employing the continuation method (CM) with an adaptive step size control algorithm. The research incorporates free-play nonlinearity at the plunge hinge, a common structural nonlinearity in aeronautics that can induce detrimental limit cycle oscillations (LCOs) during flight. By examining three scenarios—linear response, unhindered plunge motion, and nonlinear stiffness behavior—the study assesses the effects of free play on flutter and LCO phenomena, including discontinuity-induced bifurcations like grazing bifurcation. Additionally, the study explores parameter variation for nonlinear flutter analysis, revealing the dynamics of grazing bifurcation and its impact on LCO behavior. The research also demonstrates the method’s superior accuracy in flutter speed estimation and mode-switching identification, despite higher computational demands. The findings underscore the diminishing influence of nonlinear free-play behavior on LCO amplitude, providing insights with significant implications for aeroelastic design and aircraft safety.

Nonlinear aeroelastic analysis of a multi-element airfoil with free play using continuation method

In this study, the nonlinear aeroelastic response of a NACA0012 airfoil with leading-edge and trailing-edge control surfaces is studied numerically using a modified filtered impulse function method and continuation method. The source of nonlinearity comes from the free play behavior of both control surfaces which leads to the nonlinear properties of the structural stiffness matrix. The aerodynamic responses of these aeroelastic systems for varying oscillation frequencies are assumed to be linear for small deflections. These responses are developed using a reduced-order model by using the proposed modified filtered impulse function method on inviscid rotational flows computed using CFD methods for the Euler Equations. Key factors for maintaining accuracy using the proposed filtered impulse function are discussed with examples. The linearized aeroelastic equations are solved using the continuation method with the adaptive step size for three different situations that could arise in practice. The analysis process is conducted in the modes tracking and parameter variation separately. This study shows that compared to the airfoil with a single trailing-edge control surface in free play, the presence of the leading-edge flap motion could decrease the flutter speed and dominate the flutter mode in the absence of free play behavior. However, only slight differences could be observed from the limit cycle oscillations (LCO) analysis for which the structural nonlinearity is dominant owing to free play.

Modeling Infant Free Play Using Hidden Markov Models.

Infants' free-play behavior is highly variable. However, in developmental science, traditional analysis tools for modeling and understanding variable behavior are limited. Here, we used Hidden Markov Models (HMMs) to capture behavioral states that govern infants' toy selection during 20 minutes of free play in a new environment. We demonstrate that applying HMMs to infant data can identify hidden behavioral states and thereby reveal the underlying structure of infant toy selection and how toy selection changes in real time during spontaneous free play. More broadly, we propose that hidden-state models provide a fruitful avenue for understanding individual differences in spontaneous infant behavior.

Impact Of Schoolyard Green Space And Hardscape Design On Play Behaviors Of Urban Children

Previous studies have shown that large-scale schoolyard greening projects increase physical activity (PA) participation. However, the relative impact of nature access and schoolyard design on free play behaviors is unknown. PURPOSE: To determine how green space and specific schoolyard design features impact individual and population-level PA and social behaviors during recess. METHODS: Recess behaviors were recorded with the validated SOPLAY and SOCARP observation tools for one week at four urban Title 1 elementary schools (N = 2051): 1) 1.5% green space, 10 zones; 2) 0% green space, 8 zones; 28% green space, 10 zones; 4) 50% green space, 8 zones. Data was analyzed with linear mixed models and Pearson correlation at a significance value of 0.05. RESULTS: Sedentary levels were higher for older students at locations with fewer play areas regardless of green space square footage (1st-3rd grade: 49.5±2.9%; 4th-6th grade: 59.7±3.1%) and lower for younger students in green compared to asphalt schoolyards (52.8±1.8 vs. 47.4±1.7%) (p<0.01). More students were engaged in moderate-to-vigorous physical activity (MVPA) while playing tag (71.2±4.1%) or gymnastics/climbing/jumping/dance (58.1±3.3%) in green space and on play structures compared to traditional playground games (e.g. handball, 4-square, tetherball) on asphalt (45.6±1.7%) (p<0.001). Students spent more time in small groups (10.8±0.7 vs. 9.3±0.4 min, p<0.05) and in vigorous PA in green space vs. hardscape (2.3±0.2 vs. 1.1±0.1 min, p<0.05). Small group activity was positively correlated with the frequency of prosocial interactions (r=.158, p<0.001). In asphalt schoolyards, students spent more time vigorous when more play options were available (2.1±0.2 vs. 1.3±0.1 min, p<0.05). Although active minutes were similar between sexes in areas with trees, logs, and woodchips (girls: 4.8±0.4; boys: 5.4±0.7 min, p>0.05), boys spent more time active in both hardscape (girls: 3.6±0.2 vs. 4.9±0.2 min) and green space (girls: 5.0±0.8; boys: 6.9±0.8 min) areas designed for sport (p<0.05). CONCLUSION: Schoolyards that increase access to nature, provide diverse sport and non-sport play options, and present motor skill challenges optimize MVPA participation and positive peer interactions for both sexes and all age-groups in urban low-income elementary schools.

Nonlinear Airfoil Limit Cycle Analysis Using Continuation Method and Filtered Impulse Function

In this study, an adaptive step size control algorithm incorporated in the continuation method (CM) is developed and combined with the filtered impulse function method based on aerostructural solvers and applied to two aeroelastic analysis tasks concerned with modes tracking and parameter variation. The nonlinear limit cycle oscillation (LCO) of a NACA0012 airfoil with control surface free-play behavior is considered to illustrate how this adaptive step can achieve a balance between the stability, accuracy, and efficiency in the modes crossing region in modes tracking, the flutter point region in modes tracking, and the detrimental LCO region in parameter variation. It is shown that the computation time for modes tracking using this approach can be reduced by more than 65% while achieving almost the same estimate of the flutter speed as when using a fixed step size. The study also addresses a few unique and important phenomena in parameter variation such as modes jumping in the LCO curve that occur frequently using this adaptive step size algorithm. Furthermore, a combination of the modes tracking results to provide an estimate for the restart point for the CM solver to overcome the occurrence of possible extraneous solutions or divergence is proposed. The results of flutter analysis for linear structural system and nonlinear LCO analysis are validated against the results from experiments and the classical Theodorsen theory. The effect of viscous damping on the occurrence of detrimental LCO phenomena is also discussed and compared with the corresponding nondamping cases.

Early identification of children at risk of unintentional injury: A sensation seeking scale for children 2–5 years of age

Objective Sensation seeking is a personality attribute associated with injury in school-age children, adolescents, and adults. This study aimed to develop and evaluate the psychometric properties of a questionnaire measure of sensation seeking for young children 2–5 years of age. Methods Items tapping aspects of sensation seeking (Novelty Seeking, Behavioral Intensity, Thrill Seeking) were developed, content validation was completed by child development experts, and 72 parents then completed the Sensation Seeking Scale for Young Children (SSSYC) twice (3 months intervening) to establish internal and test–retest reliabilities. To assess criterion validity, scores were related to children's preferences for high versus low sensation seeking activities, their free play behavior in an indoor playroom, and to children's history of unintentional injuries. Results Indices of internal reliability and test–retest reliability were good and questionnaire scores positively correlated with sensation seeking behaviors during free play, preferences for high versus low sensation seeking activities, and injury measures, providing support for criterion validity. Conclusion This initial evaluation of the SSSYC suggests that it is a psychometrically sound measure of sensation seeking. This scale may be useful for identifying high sensation seekers at young ages, providing the opportunity for early intervention to prevent unintentional injuries.

Perturbation of Japanese mother-infant habitual interactions in the double video paradigm and relationship to maternal playfulness

Double video paradigm (DVP) studies have found contradictory evidence regarding the young infants’ ability to discriminate their mother's ‘replay’ image from ‘live’. This study examined the hypothesis that 4-month-old infants whose mothers showed high-levels-of-playful-behavior are more likely to discriminate social contingency in the DVP. We also examined the relationships between the infants’ DVP behaviors and mothers’ free-play behaviors at home with their 3-month-old infants. The results supported our hypothesis. Further, when the mothers’ behaviors were reduced to playful companion (PC) and sensitive support (SS) by a principal component analysis, the level of PC was closely related to the infants’ detection of social contingency, but SS was not. The different functions of mothers’ ‘playfulness’ and ‘sensitivity’ in communication with their infants are discussed.

Do you "want" to play? Distinguishing between conflicted shyness and social disinterest in early childhood.

This study attempted to distinguish two types of social withdrawal in early childhood: (a) one based on social fear and anxiety despite a desire to interact socially (conflicted shyness) and (b) one based on the lack of a strong motivation to engage in social interaction (social disinterest). Two samples of preschoolers (n = 119 and n = 127) 3-5 years of age participated. Their mothers completed the newly developed Child Social Preference Scale, which was designed to assess conflicted shyness and social disinterest. Maternal ratings of child temperament, parenting style, and social goals, teacher ratings of child social adjustment, observations of child free-play behaviors, and child interview assessments of perceived competence and preference for playing with peers were also collected. Distinct patterns of associations were found between conflicted shyness and social disinterest and outcome variables. Implications for the motivational underpinnings and adjustment outcomes of shyness and social disinterest are explored.

Play and social skills in maltreated and non-maltreated preschoolers during peer interactions☆

Objective: The goal of the study was to investigate whether maltreated children differ from nonmaltreated children with regard to their social skills and play behaviors.Method: The social skills and free-play behaviors of 30 3- to 5-year-old maltreated and nonmaltreated children were compared. Fifteen children with a range of maltreatment experiences drawn from a hospital-based therapeutic nursery treatment program and 15 demographically similar children drawn from a home-based Head Start program participated in the study. All children were of low socioeconomic status. Children’s free-play peer interactions were videotaped during the first 3 months of attendance in either program and analyzed along social and cognitive dimensions. Teachers and therapists rated children’s social skills in peer interactions.Results: Maltreated children were found to have significantly poorer skill in initiating interactions with peers and maintaining self-control, as well as a greater number of problem behaviors. Significant differences were not found between groups with regard to social participation or cognitive level of play. Significant correlations of moderate strength were found between social participation in play and social skills for the sample as a whole: total social skills score was positively related to interactive play, and negatively related to solitary play.Conclusion: The results suggest that the experience of maltreatment has a negative impact on children’s developing interpersonal skills above and beyond the influence of factors associated with low socioeconomic status and other environmental stressors.

Day care experience and free play behavior in preschool children

Relation of early childrearing and later play behavior were examined. Forty 3-year-old children, half of whom went to day-care centers and half of whom did not, were observed during free play activity in preschool educational settings. Both cognitive and social aspects of play were considered. As regards the former, type of play—as classified by Smilansky's structural play scheme—level of play, and thematic unit were examined. As regards the second, social participation—as classified according by Parten's social play categories—was examined. Results showed that children who went to day care played symbolically, at high a level, with long thematic units, and in interaction with peers more than children who did not. Moreover, a greater number of children in the day-care group played symbolically and in more advanced forms than children in the other group. These results were discussed in the light of the importance for the child of playing with peers during early infancy and the consequent importance of giving the infant the opportunity to attend day care.

Emotionality, emotion regulation, and preschoolers' social adaptation

AbstractIt was proposed that the interaction between the constructs of emotion regulation and social interaction would predict social adaptation in preschoolers. Ninety-six 4-year-olds were observed in quartets of unfamiliar same-sex peers. Based on parent temperament ratings and observed free play behaviors, 68 children from the original sample were classified as: low social interaction, good emotion regulators; low social interaction, poor emotion regulators; high social interaction, good emotion regulators; high social interaction, poor emotion regulators; or average. The results indicated that the low social interaction children who were poor regulators displayed more wary and anxious behaviors during free play and other episodes, and were rated as having more internalizing problems than both the low social interaction children who were good regulators and the average group. The high social interaction children who were poor regulators were rated as having more externalizing problems than either the high social interaction children who were good regulators or the average group. Thus, it seems as if emotion dysregulation is associated with psychological maladaptation, but that this association is tempered by the degree to which children engage in social interaction.

Play Skills of Preschool Children with Speech and Language Delays

The Preschool Play Scale (PPS) was used to rate the free play behaviors of 21 children with typical language development (control group) and 21 children with speech-language delays (study group) who were three and four years of age. Prior to being scored on the PPS, each child was individually observed for 3 0 minutes of outdoor free play and 3 0 minutes of indoor free play. After the observations, additional information for five categories on the PPS was obtained from a teacher observation check list complete the scoring process. The following general research question was addressed: Will children who have speech -language delays and children with typical language development differ in play age and dimension scores on the PPS? Statistically significant differences were found in the play age, in all dimension scores, and for 1 4 of the 1 6category scores. The control group consistently scored approximately one year higher than the children with speech - language delays. Some practical play intervention st...

Are Individual Differences in Fantasy Play Related to Peer Acceptance Levels?

Individual differences in fantasy play, as they relate to cognitive competence and peer acceptance, were examined in a sample of 66 children between the ages of 4 and 8 years. Each child's free-play behaviors were videotaped and then coded for frequency of fantasy play and nonfantasy play, as well as for the unreality level and unfamiliarity level of the fantasy play. Solitary play was rarely observed; therefore all play measures that were coded were social (i.e., play involving at least one partner). Cognitive competence measures included self-ratings and teacher ratings of academic skills. Peer acceptance measures included self-ratings and teacher ratings of friendships and social activities. Results showed that high-fantasy players had higher self-ratings of peer acceptance than did average-fantasy players. High-fantasy players, however, had lower teacher ratings of peer acceptance than did average-fantasy players. These differential relations could be related to an inability on the part of high-fantasy players to distinguish imagined popularity from actual peer acceptance levels. Future research is recommended to provide more detailed characterizations of individual differences in fantasy play and how they relate to outcomes in the social, cognitive, and affective domains.

Brief report free-play behavior in inhibited and uninhibited children

Four-month-old infants were classified on motor activity and frequency of crying to visual and auditory stimuli. The subgroups that were either high or low on both variables were observed at 14 months during a free-play period in an unfamiliar playroom. Five free-play variables were combined to produce a composite on which a high score was indicative of behavioral inhibition. The infants who had been high in motor activity and crying at 4 months had higher inhibition scores than did the infants with the opposite profile.

The Effects of Literacy Play Interventions on Preschoolers' Play Patterns and Literacy Development

This study investigated the effects of two types of intervention on preschoolers' play patterns and literacy development. Theme-related literacy materials were added to the dramatic play areas used by 32 children in one teacher's morning and afternoon preschool classes. The two classes were randomly assigned to different treatments: (a) Materials Only, in which literacy materials were available in play areas, but no attempt was made by the teacher to encourage children to use the materials in their play; and (b) Materials Plus Adult Involvement, in which the teacher used suggestions and modeling to encourage children to incorporate the literacy materials into their dramatic play. Before and after the 20-week treatment period, assessments were made of the children's free play behavior and literacy development. Six months later, the literacy assessments were administered for a third time. Quantitative and qualitative play observations revealed that the Materials Plus Involvement treatment was more effective in encouraging literacy-related play than the Materials Only intervention. Analysis of the literacy assessments indicated that, while both groups made significant gains over time, there were no significant between-group differences.

Breastfeeding and mother-infant interactions

Abstract This study investigated the proposition that breastfeeding facilitates mother-infant interaction in a context beyond feeding. The free-play behaviors of 11 mother-infant pairs in which infants were currently breastfed were compared to 16 bottlefeeding dyads. Coded maternal behaviors included positive instances of play, touch, vocalizations and affect directed towards the infants, and positive vocalizations, reaching and affect by the infants to their mothers. Analyses revealed that currently breastfed mother-infant pairs displayed more maternal touch and less infant vocalizing, but more fussiness. However, breastfed males and bottlefed females exhibited the most optimal behaviors, suggesting a sex by feeding interaction effect. The results are discussed with respect to the developing mother-infant relationship.

The relationship of day care quality to children's free-play behavior and social problem-solving skills

The relationship of day care quality to the activities of 4-year-old children during free play and their knowledge of social problem solving was investigated. The subjects were 55 children attending 15 day care centers and nursery school. Indicators of day care quality included quality of interaction with teachers, arrangement of the physical space, spaciousness of the environment, appropriateness and variety of the materials provided for play, quality of the outdoor area, group size, and child-teacher ratio. Relationships were found between these dimensions and children's absorption in solitary play and knowledge of social problem solving. Most of these relationships held up after the effects of social class were statistically removed.

Relations among mastery assessed during problem solving, attachment security, and free-play behavior

Relations among mastery assessed during problem solving, attachment security, and free-play behavior

The lack of effects of enriched and automated environments on the adaptive and maladaptive behavior of mentally retarded persons

AbstractThis study addressed the relative effects of repeated exposures to an austere institutional dayroom, a toy enriched dayroom, a PUSH (Play Units for the Severely Handicapped) room that contained automated stimulation devices within a physical terrain, and a modular room that contained wall mounted automated stimulation devices, on the adaptive and maladaptive freeplay behavior of six groups of institutionalized mentally retarded individuals (N = 6 per group). Group One was observed in all four settings, whereas the other five were observed in two or more of the active settings. The results indicated that (1) there were only slight differences in object‐directed adaptive behavior when the three active settings were compared to the austere setting, and (2) only the higher functioning subjects (Group Five) displayed consistent individual differences on any of the measures when active settings were compared. None of the comparisons, however, revealed statistically significant effects. This study clearly demonstrates the need for active control conditions, raises questions regarding the relevance of much of the previous research, and suggests that further refinements will be necessary before environments such as those in the present study produce meaningful changes in appropriate environmental interaction in the absence of staff mediation.

Cross-sectional and longitudinal observations of activity level and sustained attention in a normative sample.

This study examined developmental changes in playroom observations of activity level and sustained attention among 47 elementary school-age boys. The boys were observed at two different times, approximately 2 years apart. The playroom observations consisted of two 15-minute periods, a relatively unstructured freeplay period and a structured restricted academic period. In general, both cross-sectional and longitudinal analyses suggested developmental improvements in the observed behaviors. Both gross and fine motor activity decreased with increasing age, while the time spent on task increased. Consistent with the selective attention literature, there appeared to be a dramatic increase in the boys' ability of focus attention at around age 11. Finally, most of the behaviors in the restricted academic period showed significant stability over time, whereas few of the free-play behaviors did so.