Ground reaction forces and kinematics of plant leg position during instep kicking in male and female collegiate soccer players     

Heidi Orloff  Bryce Sumida  Janna Chow  Lalae Habibi  Aaron Fujino  Brian Kramer 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(2):238-247

The players' ability to achieve the greatest distance in kicking is determined by their efficiency in transferring kinetic energy from the body to the ball. The purpose of this study was to compare the kinetics and kinematics of the plant leg position between male and female collegiate soccer players during instep kicking. Twenty-three soccer players (11 males and 12 females) were filmed in both the sagittal and posterior views while performing a maximal instep kick. Plant leg kinetic data were also collected using an AMTI 1000 force platform. There were no significant differences between the sexes in plant leg position, but females had significantly greater trunk lean, plant leg angle, and medial-lateral ground reaction force than the males. Males showed higher vertical ground reaction forces at ball contact, but there were no significant differences in ball speed at take-off between the sexes. Ball speed at take-off was inversely related to peak anterior–posterior ground reaction force ( ? 0.65). The anatomical differences between the sexes were reflected in greater trunk lean and lower leg angle in the females.  相似文献   

Effect of terrain and building structures on the airflow in an airport     

Dennis Y. C. Leung  W. Y. Lo  W. Y. Chow  P. W. Chan 《浙江大学学报(A卷英文版)》2012,13(6):461-468

The aim of this study was to perform computational fluid dynamics (CFD) simulations on the airflows at the Hong Kong International Airport (HKIA). In particular, the effects of hangar buildings and terrain were studied to explore the effects of turbulence on flying aircraft, especially during landing. The CFD simulation showed that significant differences in wind speeds may occur between the north and the south runways on the western part of the HKIA under typhoon conditions with a strong north to northwesterly wind. Simulation also showed that the hanger buildings between the two runways on the western side and the nearby terrain could be causing the observed difference in the wind speeds. The results also indicated that these obstacles could cause significant wind speed variations at the western end of the south runway. This may affect the operation of landing aircraft. The CFD results for a typical typhoon case were analyzed and found to match the wind data recorded by an aircraft landing that day.  相似文献   

Literacy Achievement during Kindergarten: Examining Key Contributors in an At-Risk Sample     

Sharon Walpole  Sy-Miin Chow  Laura M. Justice 《Early education and development》2004,15(3):245-264

This study investigated the contributions of initial literacy, oral language, and social adjustment to literacy achievement at the end of the kindergarten year. Data were collected across the kindergarten year from 48 children attending a school serving primarily children from low-income households with researchbased curriculum and intervention programs. Data were used to create latent variables to represent initial literacy, oral language, and social adjustment as predictor variables and a variable representing word reading and spelling as an outcome variable. Multiple regression indicated that only initial literacy contributed significantly to the outcome. Path analysis also indicated the significance of initial literacy while supporting the shared contribution of oral language to the literacy outcome. Discriminant function analysis indicated that individuals with higher scores on the literacy outcome had high factor loadings on both initial literacy and oral language. Social adjustment did not contribute significant variance to the literacy outcome in any of the analyses. This study has implications for both policy and practice, documenting the importance of initial literacy skills, even from the beginning of kindergarten, to kindergarten literacy outcome and highlighting the correlation between the effects of initial literacy and oral language on reading and spelling.  相似文献   

Environmental education in primary schools: a case study with plastic resources and recycling     

Winnie Wing Mui So  Stephen Cheuk Fai Chow 《Education 3-13》2019,47(6):652-663

This paper aims to examine teachers’ use of strategies and approaches in integrating Plastic Resources Education (PRE) into primary school life in order to overcome the challenges encountered during implementation to promote environmentally friendly practices. Case studies with eight Hong Kong teachers from PRE-participating primary schools were invited to take part in focus group interviews, to explicate their personal stories and experiences associated with the PRE implementation in primary schools. Based on the data collected from the teachers’ sharing, several challenges which are commonly reported in the previous literature, including lack of time, shortage of manpower, and insufficient pupil engagement were found. The teachers tackled the barriers by using different strategies to improve pupils’ involvement as well as getting support from the relevant stakeholders of school management and parents. The case studies provide crucial and relevant information which can be used as a reference for other schools to integrate PRE more efficiently to facilitate learning.  相似文献   

Designing a Responsive e-Learning Infrastructure: Systemic Change in Higher Education     

Anthony S. Chow  Rebecca A. Croxton 《The American journal of distance education》2017,31(1):20-42

As university administrators respond to increasing demands of the educational market to offer greater opportunities for online learning, their capacity to create an economically stable, sustainable, yet rich teaching and learning environment deserves immediate and continued attention. A university-wide study involving 130 participants examined the e-learning perceptions and needs of faculty, students, and staff as part of a needs assessment of the e-learning unit. Results suggest that faculty recognize the importance of e-learning, that students covet it for its convenience, and that real-time technology support was the top priority. Both the school and university resources, however, are not well aligned to meet these needs and remain largely separate and unintegrated. Implications suggest a need to increase the overall ease of use for the adoption of e-learning as a new technology for teaching and learning of both faculty and students and more closely aligned department and university resources.  相似文献   

Methodological Approaches to Comparing Pedagogical Innovations Using Technology     

Nancy Law  Angela Chow  Allan H. K. Yuen 《Education and Information Technologies》2005,10(1-2):7-20

The study of educational innovations has become increasingly important in education research as many countries around the world have embarked on education reforms that aim to change both the goals and practices in education. There is also a general expectation that such innovations can be leveraged or supported by the use of information and communication technology (ICT) in the learning and teaching process. However, comparative studies of innovations are relatively rare. SITES M2, as an international comparative study of innovative pedagogical practices involving 28 participating systems, thus faced important methodological challenges the solution of which was no less an innovation in itself. This paper examines the methods of analysis used and the kind of research findings that resulted from the work of three research teams that had conducted comparisons of the case studies of innovation collected, including the work of the SITES M2 International Coordinating Centre (ICC). Even though all three studies attempted to examine similarities and differences across multiple case studies, the analysis conducted by the ICC looked for characterizations of the innovations while the other two studies developed meaningful ways to compare the cases in terms of levels of innovation across a number of dimensions. In discussing the methodological differences across these studies, this paper pays special attention to how one could compare different innovations in terms of their levels or extents of innovation and what such comparisons may contribute to our learning from technology-supported education innovations.  相似文献   

Image Capital,Field, and the Economies of Signs and Space     

Carol Pui-Ha Chow 《The Communication Review》2013,16(4):251-270

Drawing upon the concept of cultural capital, this article develops image as a form of Bourdieusean capital to examine what Lash and Urry identify as the economies of signs and space. Image capital refers to the accumulated labor of visual resources that allows agents possessing it to yield power. The concept of image capital will differentiate the power of images from the power of linguistic signs in the age of mediation.  相似文献   

Combining Cultural Analytics and Networks Analysis: Studying a Social Network Site with User-Generated Content     

Almila Akdag Salah  Lev Manovich  Albert Ali Salah  Jay Chow 《广播与电子媒介杂志》2013,57(3):409-426

Humanities and social sciences require new research approaches to deal with and to benefit from the explosion of digital media. Thanks to large scale data storage and processing, close reading of individual items can be supplemented with analysis of broader trends from massive amounts of data. Cultural Analytics (CA) is a recently developed methodology for the exploration of content and visual form in large image and video collections. It has already been applied to a variety of media types, including TV programs, feature films, newspapers, and video games. However, until now these applications did not take into account the social context of media. In many cases, media artifacts under scrutiny are generated or used by people in a social setting, either in forms of (digital) communities, or in terms of social relations, which can be also analyzed as a valuable source of information. Social network analysis (SNA) is a set of methods for the analysis of human networks, including massive online social networks. In this article, we argue that CA and SNA can be combined synergistically, using data and images from deviantArt, the leading online network of user-created art, as a case study.  相似文献   

A novel scale to assess resistance-exercise effort     

Daniel A. Hackett  Nathan A. Johnson  Mark Halaki  Chin-Moi Chow 《Journal of sports sciences》2013,31(13):1405-1413

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Kinematic analysis of shot-putting performed by wheelchair athletes of different medical classes     

John W. Chow  Woen-Sik Chae  Michael J. Crawford 《Journal of sports sciences》2013,31(5):321-330

The aim of this study was to identify those kinematic characteristics that are most closely related to an athlete's medical classification and measured distance of a put. Two S-VHS camcorders (60 fields per second) were used to record the performance of 17 males of different classes. Each participant performed six trials and the best trial for each was selected for analysis. Three-dimensional kinematics of the shot and upper body segments at the instant of release and during the forward thrust (delivery) were determined. The average speeds and angles of the shot at release for different classes (5.3-7.8 ms -1 and 21.2 to 34.4°, respectively) were smaller than those exhibited by elite male able-bodied throwers. The height of the shot at release, the angular speed of the upper arm at release, the range of motion of the shoulder girdle during the delivery, and the average angular speeds of the trunk, shoulder girdle and upper arm during the delivery, were all significantly correlated with both the classification and measured distance ( P ? 0.05). The results indicate the importance of achieving a high average angular speed for each upper body segment during the delivery.  相似文献