Analytical and experimental studies of acoustic performance of segmented liners in a compressor inlet

The performance of axially segmented (phased) acoustic treatment liners in the inlet of a compressor was investigated. Topics discussed include: (1) the validation of a theoretical procedure to predict propagation and suppression characteristics of duct liners; (2) the in-duct measurement of spinning modes; (3) investigation of phased treatment designs; (4) high Mach inlet acoustic tests; and (5) an experimental investigation of inlet turbulence. The analytical prediction for the multi-segmented treatment was found to provide the correct order of magnitude of suppression and was generally within 50% of that determined experimentally. Refinements required to improve the correlation are identified. Suppression due to high subsonic Mach number flow effects was found to become significant above an average throat Mach number of 0.65 to 0.7 and 20 PNdB was achieved with an average throat Mach number in the range of 0.80 to 0.85. For the measured turbulence in the inlet, including the axial and circumferential turbulence intensities and the axial integral length scale, data are presented with and without an inlet screen showing that the screen reduced the turbulence intensities and that the BPF noise was reduced as a consequence

Preschool children\u27s foreign language vocabulary learning by embodying words through physical activity and gesturing

Research has demonstrated that physical activity involving gross motor activities can lead to better cognitive functioning and higher academic achievement scores. In addition, research within the theoretical framework of embodied cognition has shown that embodying knowledge through the use of more subtle motor activities, such as task-relevant gestures, has a positive effect on learning. In this study, we investigated whether combining both physical activities and gestures could improve learning even more in a 4-week intervention program on foreign language vocabulary learning in preschool children. The main hypothesis that learning by embodying words through task-relevant enactment gestures and physical activities would be perceived as the preferred teaching method and lead to higher learning outcomes than learning by embodying words through task-relevant enactment gestures only, and learning without physical activities or gestures was confirmed by the results. The results of this study hold great promise for instructional methods combining physical activities and gestures as enhancers of children\u27s learning

Embodied learning in the classroom: Effects on primary school children’s attention and foreign language vocabulary learning

Objectives: The aim of the present study was to investigate the effects of specifically designed physical activities on primary school children’s foreign language vocabulary learning and attentional performance. Design: A total of 104 children aged between 8 and 10 years were assigned to either (a) an embodied learning condition consisting of task-relevant physical activities, (b) a physical activity condition involving task-irrelevant physical activities, or (c) a control condition consisting of a sedentary teaching style. Within a 2-week teaching program, consisting of four learning sessions, children had to learn 20 foreign language words. Method: Children were tested on their memory performance (cued r

Слабка збіжність сім'ї напівмарковських процесів до дифузійного процесу

Наведено основні критерії слабкої збіжності сім'ї напівмарковських процесів до ''чисто'' дифузійного процесу в умовах балансу та до дифузійного процесу Орнштейна–Уленбека за умови, що величина стрибка залежить від параметра серії ε.Приведены основные критерии слабой сходимости семейства полумарковских процессов к ''чисто'' диффузионному процессу в условиях баланса и к диффузионному процессу Орнштейна–Уленбека при условии, что величина скачка зависит от параметра серии ε.The basic criteria of weak convergence of a family of semi-Markov processes to the ''pure'' diffusion process under balance conditions and to the Ornstein–Uhlenbeck diffusion process provided that the value of jump depends on the series parameter ε are obtained

Investigating Differences between Graphical and Textual Declarative Process Models

Declarative approaches to business process modeling are regarded as well suited for highly volatile environments, as they enable a high degree of flexibility. However, problems in understanding declarative process models often impede their adoption. Particularly, a study revealed that aspects that are present in both imperative and declarative process modeling languages at a graphical level-while having different semantics-cause considerable troubles. In this work we investigate whether a notation that does not contain graphical lookalikes, i.e., a textual notation, can help to avoid this problem. Even though a textual representation does not suffer from lookalikes, in our empirical study it performed worse in terms of error rate, duration and mental effort, as the textual representation forces the reader to mentally merge the textual information. Likewise, subjects themselves expressed that the graphical representation is easier to understand

Establishing a Scientific Consensus on the Cognitive Benefits of Physical Activity

Research suggests that physical activity can be used as an intervention to increase cognitive function. Yet, there are competing views on the cognitive effects of physical activity and it is not clear what level of consensus exists among researchers in the field. The purpose of this study was two-fold: Firstly, to quantify the scientific consensus by focusing on the relationship between physical activity and cognitive function. Secondly, to investigate if there is a gap between the public's and scientists' interpretations of scientific texts on this topic. A two-phase study was performed by including 75 scientists in the first phase and 15 non-scientists in the second phase. Participants were asked to categorize article abstracts in terms of endorsement of the effect of physical activity on cognitive function. Results indicated that there was a 76.1% consensus that physical activity has positive cognitive effects. There was a consistent association between scientists' and non-scientists' categorizations, suggesting that both groups perceived abstracts in a similar fashion. Taken together, this study provides the first analysis of its kind to evaluate the level of consensus in almost two decades of research. The present data can be used to inform further research and practice

Gesturing during mental problem solving reduces eye movements, especially for individuals with lower visual working memory capacity

Non-communicative hand gestures have been found to benefit problem-solving performance. These gestures seem to compensate for limited internal cognitive capacities, such as visual working memory capacity. Yet, it is not clear how gestures might perform this cognitive function. One hypothesis is that gesturing is a means to spatially index mental simulations, thereby reducing the need for visually projecting the mental simulation onto the visual presentation of the task. If that hypothesis is correct, less eye movements should be made when participants gesture during problem solvin

Relative age effects on academic achievement in the first ten years of formal schooling: A nationally representative longitudinal prospective study

The effects of school starting age and relative age effects (RAEs) have generated much interest from parents, teachers, policymakers, and educational researchers. Our 10-year longitudinal study is based on a nationally representative (N = 4,983) prospective sample from the Longitudinal Study of Australian Children. The primary outcomes are results from the high-stake, Australia-wide National Assessment Program-Literacy and Numeracy tests in Years 3, 5, 7, and 9, controlling for demographic characteristics (gender, socioeconomic status, school type, and childhood cognition measured before the start of kindergarten). We evaluated how direct and mediated RAEs vary over the first 10 years of schooling for these longitudinal data. Results revealed significant RAEs in primary school years for both numeracy and literacy test outcomes. Effects were large in primary school years but declined in secondary school years. Although the direct effects of RAEs declined over time, there continued to be significant indirect effects over the whole 10-year period. RAEs in primary school had enduring effects that were mediated through the effects of earlier achievement. We juxtapose our results with previous RAE research on achievement and a range of other noncognitive outcomes where the RAEs are enduring into adolescence and even adulthood. We position our research within this broader research literature and discuss implications for educational policy, practice, theory, and future research

Effects of integrated physical exercises and gestures on preschool children’s foreign language vocabulary learning

Research suggests that integrating human movement into a cognitive learning task can be effective for learning due to its cognitive and physiological effects. In this study, the learning effects of enacting words through whole-body movements (i.e., physical exercise) and part-body movements (i.e., gestures) were investigated in a foreign language vocabulary task. Participants were 111 preschool children of 15 childcare centers, who were randomly assigned to one of four conditions. Participants had to learn 14 Italian words in a 4-week teaching program. They were tested on their memory for the words during, directly after, and 6 weeks after the program. In the integrated physical exercise condition, children enacted the actions indicated by the words to be learned in physical exercises. In the non-integrated physical exercise condition children performed physical exercises at the same intensity, but unrelated to the learning task. In the gesturing condition, children enacted the actions indicated by the words to be learned by gesturing while remaining seated. In the conventional condition, children verbally repeated the words while remaining seated. Results confirmed the main hypothesis, indicating that children in the integrated physical exercise condition achieved the highest learning outcomes. Implications of integrated physical exercise programs for preschool children’s cognition and health are discussed

Watch your step children! learning two-digit numbers through mirror-based observation of self-initiated body movements

It was investigated whether task-related body movements yield beneficial effects on children’s learning of two-digit numbers and whether these learning effects are affected by mirror-based self-observation of those movements. Participants were 118 first-graders, who were randomly assigned to two movement conditions and two nonmovement control conditions. In the movement conditions, children were instructed to build two-digit numbers by making and simultaneously verbalizing out loud different sized steps representing the smaller units the numbers consisted of (e.g., the number “B36” was construed by saying out loud “B10,” “B20”, “B30,” “B35,” “B36,” while making three big steps, one medium, and one small step) on a ruler across the floor. In one of the movement conditions, the children were additionally asked to observe their steps in a mirror. In the first conventionally taught control condition, the children were asked to verbally build and mark the two-digit numbers on a ruler depicted on a sheet of paper. In the second control condition, children were seated before the ruler across the floor, and after verbally constructing the two-digit number, they had to walk to the appropriate position of the number on the ruler across the floor. In the subsequent test phase, children’s knowledge of two-digit numbers was assessed by a final math test. The results confirmed the hypothesis that the movement conditions lead to higher test performance than the non-movement condition and revealed that test performance was not differentially affected by mirror-based self-observation