169 research outputs found
Impact of Georgia's Pre-K Program on Kindergarten through Third Grade Teachers
The Georgia Prekindergarten Program (Pre-K), established in 1993, provides Georgia's fouryear-old children with high quality preschool experiences in order to prepare them for kindergarten. Immediate gains resulting from Pre-K can be lost if teachers in later grades are not prepared to capitalize on the increasing capabilities of students. To sustain the positive effects of the Pre-K program, teachers in later grades need both to recognize that students are better prepared for school and to adapt their instructional practices to take advantage of their students' increasing capabilities. Research implies that teachers adopt practices in their classrooms relative to how their beliefs match assumptions inherent in new programs. Thus, this study investigates teacher awareness of the impact of Pre-K on students, teacher beliefs about instructional practices, current instructional practices, and the relationship between beliefs and practices.The Council for School Performance launched this study to examine the implications of the Pre-K program for teachers of children in kindergarten through third grade. Through a survey of teachers in Georgia, the Council has found that teachers believe that the Pre-K program has positively affected students in elementary school, despite observations that students are, overall, changing for the worse. The majority of teachers believe in child-centered instructional practices, but this belief has not been adopted into their own instructional practices. Overall, teachers are as likely to use child-centered practices as they are to use teacher-directed activities
Pressure evaluation of spray induced flow by means of URANS and time-resolved Stereo Particle Image Velocimetry
In the present work, pressure distributions of spray-induced flow are obtained by means of time-resolved stereo Particle Image Velocimetry. Revealing an extensive insight in the nature of spray transport, the characterization of pressure, material acceleration and instantaneous velocity provides a comprehensive description of spray induced flow dynamics. The pressure evaluation is conducted by an extended formulation based on the Unsteady Reynolds Averaged Navier-Stokes Equations and ensemble averaging. Assuming adiabatic flow and perfect gas the effect of compressibility is taken into account. In order to achieve phase discrimination and image contrast enhancement, optical filtering is applied by doping the gaseous phase with fluorescent tracer particles. The measurements are performed with gasoline direct injection 2-hole research samples. Demonstrating the capacity of pressure evaluation, pressure fields of spray-induced flow are successfully obtained. The investigations reveal characteristic flow patterns in accordance to air entrainment and fluid displacement. In respect to single spray plumes, high pressure regions are identified in front of the spray and the wake flow, whereas low pressure regions are present at central position. The pressure evaluation exposes minimal pressure differences
Analysis of spray induced flow of gasoline direct injection (GDI) nozzle by means of time-resolved Fluorescence-Particle Image Velocimetry
The development of modern gasoline direct injection (GDI) nozzles demands profound knowledge about the mechanisms of spray transport in order to minimize emissions and maximize fuel efficiency. To receive a fundamental understanding about spray transport, the present study investigates spray induced flow of a two-hole research nozzle. Air entrainment, spray-air interaction and jet-to-jet interaction are analyzed by means of timeresolved Fluorescence-Particle Image Velocimetry (FPIV). In order to achieve phase discrimination, optical filtering is applied by doping the gaseous phase with fluorescent seeding particles. The investigation considers near field and global spray characteristics by using different field of views and optical magnifications. Flow features such as displacement and entrainment are identified and localized, providing a description of strength, growth and propagation. The exchange of momentum between spray and gas indicates jet-to-jet interaction by attraction of separate spray plumes. The investigation demonstrates a dependency between spray hole inclination angle and entrainment flow. Spray plumes with smaller inclination angels tend to be more attracted than spray plumes with higher inclination angels. A disparity of momentum exchange is observed
An assessment of the correlation-based particle identification (CPI) method in the framework of Dual-Plane Stereo-Astigmatism (DPSA)
A synthetic study is conducted to assess the performance of the correlation-based particle identification method (CPI). As a technique developed in the context of Dual-Plane StereoAstigmatism (DPSA), the CPI method allows the identification of particle image shapes by utilizing image cross-correlation. The performance assessment addresses the influence of noise, particle density, particle image size and particle image deformation. The study shows viable results for low to moderate particle densities. Generally, a stronger performance of the CPI method is observed for small particle image sizes and pronounced particle image deformations. However, in the absence of particle overlapping, such as in the case of small particle densities, bigger particle images show a
stronger performance, since a finer numerical discretization of the particle image provides a more accurate computation of the image cross-correlation. A stronger incorporation of particle overlapping increases the rate of particle identification, however it diminishes the accuracy of particle localization and particle allocation
You made him be alive: Children’s perceptions of animacy in a humanoid robot
Social robots are becoming more sophisticated; in many cases they offer complex, autonomous interactions, responsive behaviors, and biomimetic appearances. These features may have significant impact on how people perceive and engage with robots; young children may be particularly influenced due to their developing ideas of agency. Young children are considered to hold naive beliefs of animacy and a tendency to mis-categorise moving objects as being alive but, with development, children can demonstrate a biological understanding of animacy. We experimentally explore the impact of children’s age and a humanoid’s movement on children’s perceptions of its animacy. Our humanoid’s behavior varied in apparent autonomy, from motionless, to manually operated, to covertly operated. Across conditions, younger children rated the robot as being significantly more person-like than older children did. We further found an interaction effect: younger children classified the robot as significantly more machine-like if they observed direct operation in contrast observing the motionless or apparently autonomous robot. Our findings replicate field results, supporting the modal model of the developmental trajectory for children’s understanding of animacy. We outline a program of research to both deepen the theoretical understanding of children’s animacy beliefs and develop robotic characters appropriate across key stages of child development
Implementing a new mathematics curriculum in England: district Research Lesson Study as a driver for student learning, teacher learning and professional dialogue.
Against a backdrop of a transformation in teacher professional development and learning and state school organisation in England this century, this chapter describes a project which harnessed six cycles of Research Lesson Study at school and district level over two years to tailor the implementation of a new statutory curriculum in England to address the professional development needs of teachers and classroom learning needs of London students. It also reports the findings of research carried out during the project into how these teachers learned and developed this new curricular expertise and practice- knowledge through lesson study dialogues that supported student learning. It concludes by proposing future directions for teacher professional learning research and practice
Impact of High Mathematics Education on the Number Sense
In adult number processing two mechanisms are commonly used: approximate estimation of quantity and exact calculation. While the former relies on the approximate number sense (ANS) which we share with animals and preverbal infants, the latter has been proposed to rely on an exact number system (ENS) which develops later in life following the acquisition of symbolic number knowledge. The current study investigated the influence of high level math education on the ANS and the ENS. Our results showed that the precision of non-symbolic quantity representation was not significantly altered by high level math education. However, performance in a symbolic number comparison task as well as the ability to map accurately between symbolic and non-symbolic quantities was significantly better the higher mathematics achievement. Our findings suggest that high level math education in adults shows little influence on their ANS, but it seems to be associated with a better anchored ENS and better mapping abilities between ENS and ANS
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