Analysis of a load application point in spline coupling teeth     

Francesca CURà  Andrea MURA 《浙江大学学报(A卷英文版)》2014,15(4):302-308

The objective of this paper is to investigate the position of the resultant force in involute spline coupling teeth due to the contact pressure distribution for both ideal and misaligned conditions. In general, spline coupling teeth are in contact all along the involute profile and the load is far from uniform along the contact line. Theoretical models available in publications consider the resultant contact force as it is applied at the pitch diameter, and this study aims to evaluate the error introduced within the confines of a common approximation environment. This analysis is carried out through using finite element method （FEM） models, considering spline couplings in both ideal and misaligned conditions. Results show that the differences between the load application diameter and pitch diameter are not very obvious in both ideal and misaligned conditions; however, this ap- proximation becomes more important for the calculation of the tooth stiffness.  相似文献   

Agenda Setting and Priming Effects Based on Information Presentation: Revisiting Accessibility as a Mechanism Explaining Agenda Setting and Priming     

Francesca R. Dillman Carpentier 《Mass Communication and Society》2014,17(4):531-552

In three experiments, this investigation evaluated the sufficiency of construct accessibility in explaining individual-level agenda setting and priming outcomes. Participants were exposed to an issue presented within a story from a respected news source (e.g., New York Times), a story from an unknown individual's blog, a story from a respected non-news organization (e.g., National Geographic), a crossword puzzle from a respected news source, or a crossword puzzle from an online game website. Story and crossword content was constant across the different sources. Participants responded either to a measure of implicit priming or to the traditional agenda setting question asking what the most important issue in the nation is. Priming effects were robust across presentation context, indicating a successful increase in temporary accessibility. Agenda setting effects were strongest when information came from news than from non-news sources, regardless of whether the issue was presented within a story or crossword. Findings suggest that issue salience in agenda setting is more appropriately conceptualized as perceived importance rather than top-of-mind awareness. News sources uniquely cue this salience beyond the abilities of other respected organizations.  相似文献   

The evolution of socio-economic disparities in literacy skills from age 15 to age 27 in 20 countries     

Francesca Borgonovi  Artur Pokropek 《British Educational Research Journal》2021,47(6):1560-1586

This study contributes to the literature by examining the evolution of socio-economic disparities in literacy skills between age 15 and 27. It uses combined cross-sectional data from the Programme for International Student Assessment and the Programme for the International Assessment of Adult Competencies in 20 countries and adopts a synthetic cohort approach. In the article we examine if there are differences in the evolution of socio-economic disparities in literacy between the teenage years and young adulthood among high-achieving students (90th percentile) and among low-achieving students (10th percentile) and compare differences across education systems. We used parental education as an indicator of socio-economic status. Findings indicate that on average, disparities in literacy skills observed at age 15 widen by 15% of a standard deviation by age 27. Such increase is determined by a more pronounced growth in achievement among individuals with tertiary educated parents than among individuals whose parents did not complete tertiary education. The increase in socio-economic gaps between age 15 and 27 is more pronounced among low-achieving students. The group that improves the most between age 15 and 27 is low-achieving individuals with tertiary educated parents. We find that socio-economic differences in educational attainment, NEET status and use of skills at home and in the workplace explain a large part of socio-economic disparities in literacy achievement among young adults. Although countries with above-average disparities at age 15 tend to also display above-average disparities at age 27, we identify differences across countries.  相似文献   

Perceptual completion in newborn human infants     

Valenza E  Leo I  Gava L  Simion F 《Child development》2006,77(6):1810-1821

Despite decades of studies of human infants, a still open question concerns the role of visual experience in the development of the ability to perceive complete shapes over partial occlusion. Previous studies show that newborns fail to manifest this ability, either because they lack the visual experience required for perceptual completion or because they fail to detect the pattern of motion. To distinguish these possibilities, newborns' perception of a center-occluded object was tested, using stroboscopic motion. Infants (mean age of 72 hr) perceived the object as a connected unit, providing the first evidence that the newborn is capable of filling in gaps in the visible surface layout when the relevant visual information can be detected by his or her immature visual system.  相似文献   

The Impact of the National Endowment for the Arts in the United States: Institutional and Sectoral Effects on Private Funding     

Francesca Borgonovi  Michael O'Hare 《Journal of Cultural Economics》2004,28(1):21-36

This paper examines the impact of the National Endowment for the Arts on private donations to the arts. The aim of the analysis is to assess whether public funding generates a crowding effect on private giving. We distinguish between institutional and sectoral crowding phenomena and discuss their possible implications.We used both a qualitative approach and an econometric model to estimate the effect of NEA introduction and appropriations on donations. Our results suggest that at the institutional level NEA grants do not generally induce donations to recipients while at the sectoral level appropriations and private giving are independent. The introduction of the agency appears to have caused a decrease in donations.  相似文献   

Efficacy of a cultural adaptation of the Identity Project intervention among adolescents attending multiethnic classrooms in Italy: A randomized controlled trial     

Chiara Ceccon  Maja K. Schachner  Francesca Lionetti  Massimiliano Pastore  Adriana J. Umaña-Taylor  Ughetta Moscardino 《Child development》2023,94(5):1162-1180

This registered report evaluated the efficacy of an Italian adaptation of the Identity Project, a school-based intervention promoting adolescents' cultural identity. Migration background and environmental sensitivity were explored as moderators. After adapting and piloting the intervention, a randomized controlled trial was conducted between October 2021 and January 2022 on 747 ethnically diverse adolescents (M_age = 15 years, 53% girls, 31% with migration background) attending 45 classrooms randomly assigned to the intervention or control condition. Bayesian analyses confirmed the efficacy of the Italian IP in enhancing exploration processes (Cohen's d = .18), whereas no cascading effect on resolution emerged. Youth with higher (vs. lower) levels of environmental sensitivity benefited more in terms of exploration. Implications for developmental theory and practice are discussed.  相似文献