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排序方式: 共有253条查询结果,搜索用时 15 毫秒
41.
On November 10, 2005, then Superintendent of the Kalamazoo Public School System, Janice Brown announced—to the surprise of Kalamazoo’s residents—the beginning of the Kalamazoo Promise. Fully funded by a set of anonymous donors, the Kalamazoo Promise is an urban revitalization program that offers up to four years of free tuition to any public college or university in the state of Michigan for graduates of the Kalamazoo Public School system who meet certain eligibility criteria. Using the subsidy as a source of exogenous variation in the price of college, we use quasi-experimental methods to evaluate the impact of the subsidy on college choice. We find that the Kalamazoo Promise increases the likelihood that students from Kalamazoo Public Schools consider public institutions in Michigan. In addition, we find that the Kalamazoo Promise especially impacts the college choice set of students from families who earn less than $50,000 in annual income. 相似文献
42.
Chunjia Han Stephen Rhys Thomas Mu Yang Petros Ieromonachou Hongru Zhang 《The Journal of High Technology Management Research》2017,28(1):93-109
Research and development (R&D) investment activity plays a crucial role in developing high-tech industries. In recent decades, China has made sustained investments in its domestic high-tech industries, with the goal of increasing their productivity. This paper investigates the effect of this investment on relative R&D efficiency across China's high-tech sectors. Data Envelopment Analysis (DEA) was used to generate quantitative indices for sector comparisons. The analysis of this study indicates that overall R&D investment efficiency did not increase from 1998 to 2009, despite R&D expenditure increasing by 2188%. Over the same period, most sectors suffered from decreasing returns to scale (DRS), presumably also reflecting the inefficient R&D investment. Most of the sectors showed significant fluctuation on R&D investment efficiency. This research result indicates that the problem of China's high-tech industry may be from the inefficiency of its technology commercialization processes, and therefore represents a critical parameter for policy makers and managers. 相似文献
43.
Rafael Escamilla Glen Fleisig Steven Barrentine James Andrews Claude Moorman III 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):213-228
The purpose of this study was to quantify and compare kinematic, temporal, and kinetic characteristics of American and Korean professional pitchers in order to investigate differences in pitching mechanics, performance, and injury risks among two different cultures and populations of baseball pitchers. Eleven American and eight Korean healthy professional baseball pitchers threw multiple fastball pitches off an indoor throwing mound positioned at regulation distance from home plate. A Motion Analysis three‐dimensional automatic digitizing system was used to collect 200 Hz video data from four electronically synchronized cameras. Twenty kinematic, six temporal, and 11 kinetic variables were analyzed at lead foot contact, during the arm cocking and arm acceleration phases, at ball release, and during the arm deceleration phase. A radar gun was used to quantify ball velocity. At lead foot contact, the American pitchers had significantly greater horizontal abduction of the throwing shoulder, while Korean pitchers exhibited significantly greater abduction and external rotation of the throwing shoulder. During arm cocking, the American pitchers displayed significantly greater maximum shoulder external rotation and maximum pelvis angular velocity. At the instant of ball release, the American pitchers had significantly greater forward trunk tilt and ball velocity and significantly less knee flexion, which help explain why the American pitchers had 10% greater ball velocity compared to the Korean pitchers. The American pitchers had significantly greater maximum shoulder internal rotation torque and maximum elbow varus torque during arm cocking, significantly greater elbow flexion torque during arm acceleration, and significantly greater shoulder and elbow proximal forces during arm deceleration. While greater shoulder and elbow forces and torques generated in the American pitchers helped generate greater ball velocity for the American group, these greater kinetics may predispose this group to a higher risk of shoulder and elbow injuries. 相似文献
44.
A relationship between brain responses at birth and later emerging language and reading skills have been shown, but questions
remain whether changes in brain responses after birth continue to predict the mastery of language-related skills such as reading
development. To determine whether developmental changes in the brain-based perceptual skills are systematically related to
differences in word-level reading proficiency at age 8 years, brain event-related potentials (ERPs) to speech and nonspeech
stimuli were recorded annually at the ages of 1 through 8 years in a sample of 109 typically developing children. Two measures
of word-level reading (one that requires decoding of real words and one of pseudowords) were administered at age 8 years.
Growth curve analysis, using the hierarchical linear models, related reading performance (average versus low) to the longitudinal
maturation in the ERP waveform peak and latencies. Maturational changes (e.g., slope, acceleration, and cubic growth) in N1
amplitude from ages 1 to 4 were related to proficiency in decoding pseudoword stimuli only, with children who were less proficient
in decoding pseudowords evidencing more steeply negative declines in amplitude with age, particularly at the frontal and parietal
recording sites in response to both speech and nonspeech stimuli. In contrast, proficiency in decoding real words was related
to developmental changes in N2 amplitudes from ages 4 to 8 only at the parietal recording site, and only in response to nonspeech
stimuli. The early development of biologically based differences in the perception and processing of auditory information
contributes to later group differences in reading proficiencies at school age. 相似文献
45.
46.
Opportunities to Learn in the Budapest Mathematics Classroom 总被引:1,自引:0,他引:1
Paul Andrews 《International Journal of Science and Mathematics Education》2003,1(2):201-225
This paper examines the nature of the problems posed, the processes by which their solutions were made public, their structural contribution to a lesson and the opportunities they offered for the learning of mathematics in Budapest, Hungary. The problems were derived from observations, the processes of which were informed by various comparative studies, of 94 mathematics lessons in the 10–14 age range. Problems, the analysis and categorisation of which were informed by the literature, tended to fall into two categories – single response with high levels of cognitive demand and multiple response with high levels of cognitive demand. Structurally lessons fell into a well practised pattern of classroom behaviour. They began with a public review of homework, comprising two or three multiple response problems which were solved collaboratively. This was followed by a warm-up period involving the oral setting and mental solving of a few single response problems. Lastly, the main body of the lesson involved several cycles in which a multiple response problem was posed, attempted individually before solutions were shared publicly. Lessons ended with homework being set. The discussion of the findings is framed by Hungary's variable performance on recent international tests of mathematical attainment. 相似文献
47.
This paper presents how some Australian schools are changing their approaches to leading the teaching and learning in their diverse and multi-characteristic contexts. Experiences of these schools shows that the development of a school wide approach to pedagogy and its implementation needs to be firmly embedded in the leadership of learning. Drawing on recent research conducted in the Sydney Catholic Education Office system in Australia (Crowther et al. in Leading and Managing 18(2):1–33, 2012) there is evidence of relationship between the development and implementation of a school wide approach to pedagogy and student achievement. There is also evidence to support leadership that is based on a mutualistic relationship between teacher leaders and the principal. This paper focuses on the way schools have used their visions and pedagogical frameworks to enhance whole of school quality outcomes. It highlights the power of teacher leaders taking responsibility for pedagogical development and implementation. In addition, it illustrates the power of mutualistic relationships (parallel leadership) when the principal takes responsibility for unleashing and trusting the creative expertise of teacher leaders in line with the role of strategic leadership and management. 相似文献
48.
49.
TM Andrews RM Price LS Mead TL McElhinny A Thanukos KE Perez CF Herreid DR Terry PP Lemons 《CBE life sciences education》2012,11(3):248-259
This study explores biology undergraduates' misconceptions about genetic drift. We use qualitative and quantitative methods to describe students' definitions, identify common misconceptions, and examine differences before and after instruction on genetic drift. We identify and describe five overarching categories that include 16 distinct misconceptions about genetic drift. The accuracy of students' conceptions ranges considerably, from responses indicating only superficial, if any, knowledge of any aspect of evolution to responses indicating knowledge of genetic drift but confusion about the nuances of genetic drift. After instruction, a significantly greater number of responses indicate some knowledge of genetic drift (p = 0.005), but 74.6% of responses still contain at least one misconception. We conclude by presenting a framework that organizes how students' conceptions of genetic drift change with instruction. We also articulate three hypotheses regarding undergraduates' conceptions of evolution in general and genetic drift in particular. We propose that: 1) students begin with undeveloped conceptions of evolution that do not recognize different mechanisms of change; 2) students develop more complex, but still inaccurate, conceptual frameworks that reflect experience with vocabulary but still lack deep understanding; and 3) some new misconceptions about genetic drift emerge as students comprehend more about evolution. 相似文献
50.
The development of response inhibition was investigated using a computerized go/no‐go task, in a lagged sequential design where 376 preschool children were assessed repeatedly between 3.0 and 5.25 years of age. Growth curve modeling was used to examine change in performance and predictors of individual differences. The most pronounced change was observed between 3 and 3.75 years. Better working memory and general cognitive ability were related to more accurate performance at all ages, but relations with speed changed with age, where better cognitive skills were initially related to slower responding, but faster responding at later ages. Boys responded more quickly and were more accurate on go trials, whereas girls were better able to withhold responding on no‐go trials. 相似文献