The aim of this study was to determine how shaft length affects golf driving performance. A range of drivers with lengths between 1.168 m and 1.270 m, representing lengths close to the 1.219 m limit imposed by R&A Rules Limited (2008), were assembled and evaluated. Clubhead and ball launch conditions and drive distance and accuracy were determined for seven category 1 golfers (handicaps 0.21 +/- 2.41) who performed shots on a purpose-built practice hole. As shaft length increased from 1.168 m to 1.270 m, initial ball velocity increased (+ 1.8 m/s, P < 0.01). Ball carry (+ 4.3 m, P = 0.152) also increased, although not significantly so. Furthermore, as shaft length increased, for all club comparisons there was no decrease in accuracy. Ball launch conditions of spin components and launch angle remained unaffected by shaft length. Launch angle increased (0.8 degree, F = 1.074, P = 0.362) as driver shaft length increased. Our results show that clubhead and ball velocity together with ball carry tended to increase with no loss of accuracy. 相似文献
In Australia, and internationally, integration is a widely promoted middle school curriculum reform strategy. Integration
is claimed to engage students by providing opportunities to work on a few cross-disciplinary objectives, to apply knowledge
across the subject boundaries and to work on tasks with meaning and relevance. While these curriculum goals enjoy a certain
popularity among middle school reformers and curriculum integration adherents, in practice, the prevalence of integration
is patchy and provisional. In this article, we (re) examine two of our studies of middle school integration over the past
decade to explore the reasons for this apparent disparity between the rhetoric and the reality. In our re-search for integration,
we look back at our data to identify enabling and inhibiting conditions for curriculum reform and develop a list of key program
characteristics. Finally, we look forward, drawing on the notion of institutional resilience to speculate on the reasons why
some middle school programs seem to flourish while others wither. 相似文献
Previous studies on the kinematics of the golf swing have mainly focused on group analysis of male golfers of a wide ability range. In the present study, we investigated gross body kinematics using a novel method of analysis for golf research for a group of low handicap female golfers to provide an understanding of their swing mechanics in relation to performance. Data were collected for the drive swings of 16 golfers using a 12-camera three-dimensional motion capture system and a stereoscopic launch monitor. Analysis of covariance identified three covariates (increased pelvis-thorax differential at the top of the backswing, increased pelvis translation during the backswing, and a decrease in absolute backswing time) as determinants of the variance in clubhead speed (adjusted r (2) = 0.965, P < 0.05). A significant correlation was found between left-hand grip strength and clubhead speed (r = 0.54, P < 0.05) and between handicap and clubhead speed (r = -0.612, P < 0.05). Flexibility measures showed some correlation with clubhead speed; both sitting flexibility tests gave positive correlations (clockwise: r = 0.522, P < 0.05; counterclockwise: r = 0.711, P < 0.01). The results suggest that there is no common driver swing technique for optimal performance in low handicap female golfers, and therefore consideration should be given to individual swing characteristics in future studies. 相似文献
This special issue of Archival Science examines the orientations, paradoxes, and tensions evident in the ethical struggles over the construction of the past and the degree to which archival agency can intercede in supporting a broadly drawn historical justice that also engages contemporary issues. Inspired and framed by a May 2008 conference hosted by School of Information and Labadie Collection, University of Michigan, Ann Arbor, the following essays offer case study examinations of how archival institutions and archivists contribute to societal memory systems through both their action and inaction, especially in regard to societal struggles over the meanings to be derived from the past. 相似文献
This article describes a collaborative research project by the institutional research group and a team of faculty members at a Canadian university. In response to an increasingly diverse mix of students, the researchers set out to develop an understanding of relationships between student characteristics, categorized as demographic differences, personal attributes and academic preparedness, and student outcomes measured by both grades and student perceptions. Significant differences were found in grades outcomes based on characteristics such as international status, secondary school grades, study habits and writing skills. However, these differences were not evident in student perceptions of course value or learning achievement. This study has important implications for university administrators (recruiting, intake assessment and student support), instructors (understanding of diversity characteristics and how students perceive learning experience) and for students, who can be given an opportunity to better understand how their own personal characteristics might affect their learning experiences and outcomes.
Subjects in six experimental groups (n = 16 each) received one-trial passive avoidance (PA) training in which shock was delivered upon movement from a white wooden
floor compartment to a black grid compartment. Then fear was extinguished (30 min) in the black compartment. After either
24 or 168 h, all the groups were treated in a room distinctively different from the training room. At each interval, one group
received a shock in an apparatus similar to the conditioning box, another received a shock in a dissimilar apparatus, and
another was placed in a neutral box. A PA test trial in the training apparatus indicated reinstatement of extinguished fear
in all the groups given a postextinction shock except the 24-h dissimilar group. Control groups revealed that the extinction
treatment was effective and that spontaneous recovery was not evident. The results were explained in terms of classical conditioning,
stimulus generalization, and the broadening (flattening) of stimulus generalization gradients with time. 相似文献