A constrained linear quadratic optimization algorithm toward jerk-decoupling cartridge design

Linear direct feed drives are widely used in machine tools, but an abrupt counter force from the secondary part will induce the jerk to the metro frame contacted with the linear motor and cause the vibration of auxiliary devices on it. The jerk-decoupling cartridge (JDC) provides a buffer to reduce such an impact. Design target for such a system includes both the tracking error and the jerk induced to the metro frame. To achieve both targets systematically, this work presents an integrated approach to efficiently determine parameters in the JDC and the position controller of the feed drive. The problem is firstly formulated as a nonlinear constrained optimization problem, which is then converted to a series of projection gradient optimization problems and step searching problems, which are either convex or linear. Thus, fast convergence of parameters are achieved within first several iterations. Through a series of simulation, the effectiveness of proposed methodology is verified.     

Gifted students' intrinsic and extrinsic motivations and parental influence on their motivation: from the self‐determination theory perspective

The aim of this research is to describe and investigate a sample of school gifted students' intrinsic and extrinsic motivations, and the role of their parents in fostering motivational achievements in Jordan. In the study, 122 gifted students were selected to complete a questionnaire (adapted from Pelletier, Fortier and Vallerand et al.) investigating the mentioned constructs. Results showed that students were highly intrinsically and extrinsically motivated. The results also showed significant correlation between intrinsic and extrinsic motivations and perceived competence and parental support scales except for parental control. Other interesting findings were also found regarding the aforementioned constructs. The results further reveal some significant differences in control, achievement goal, amotivation and competence support between genders and education of parents. The possible implications of and recommendations from these findings will be discussed.     

Childhood Problems in a Sudanese City: A Comparison of Extended and Nuclear Families

The relation between emotional and social development and family structure in the Sudanese capital, Khartoum, was examined. Children between the ages of 4 and 9 living in extended and nuclear families were compared on mothers' ratings of a range of childhood problems. Analysis revealed that children in nuclear families had more conduct, emotional, and sleep problems, poorer self-care, and were more likely to be overdependent than those living in extended families. They were also less likely to be breast fed, to be weaned later, and to have grandmothers involved in child care. Linear multiple regression revealed that, of these 3 childcare factors, grandmother's involvement was the strongest predictor of normal social and emotional adjustment. The possible protective characteristics of the extended family are discussed in relation to the importance of the grandmother as maternal advisor, social support, and socialization agent.     

The Relation Between Global and Specific Mindset With Reading Outcomes for Elementary School Students

An emerging body of research has evaluated the role of growth mindset in educational achievement, yet little work has focused on the unique role of mindset to standardized reading outcomes. Our study presents 4 key outcomes in a sample of 195 fourth-grade students. First, we evaluated the dimensionality of general and reading-specific mindset and found that a global factor of growth mindset (GGM) existed along with specific factors of general and reading mindset. Second, GGM and reading mindset strongly predicted word reading and reading comprehension. Third, GGM and reading mindset uniquely predicted reading comprehension after controlling for basic word reading skills. Fourth, GGM was more strongly associated with reading comprehension for those individuals with weaker reading comprehension skills, whereas reading mindset was more strongly associated with reading comprehension for those with stronger reading comprehension skills. Our findings suggest the potential importance of assessing general and reading-specific mindset linked to reading.     

Bilingual poetry: expanding the cognitive and cultural dimensions of children's learning

Stories and poetry have long been considered a resource for the language and literacy development of bilingual children, particularly if they can work with texts in both mother tongue and English. This paper demonstrates that bilingual learning is also beneficial for second and third‐generation children whose English is often stronger than their mother tongue. Presenting data from an action research project in East London primary schools, we show how children investigated metaphor and cultural content in a Bengali lullaby, clarifying concepts through dialogue with their parents. Comparison with a lullaby in English from North America generated additional ideas concerning different cultural values. The learning process enabled children to use their bilingual skills and draw on different aspects of their bicultural identities. Finally, we explain how bilingual poetry can be used to stimulate learning in a multilingual classroom context, through the example of a whole‐class lesson based around Bengali and English lullabies.