Subject-specific computer simulation model for determining elbow loading in one-handed tennis backhand groundstrokes     

King MA  Glynn JA  Mitchell SR 《Sports biomechanics / International Society of Biomechanics in Sports》2011,10(4):391-406

A subject-specific angle-driven computer model of a tennis player, combined with a forward dynamics, equipment-specific computer model of tennis ball-racket impacts, was developed to determine the effect of ball-racket impacts on loading at the elbow for one-handed backhand groundstrokes. Matching subject-specific computer simulations of a typical topspin/slice one-handed backhand groundstroke performed by an elite tennis player were done with root mean square differences between performance and matching simulations of < 0.5 degrees over a 50 ms period starting from ball impact. Simulation results suggest that for similar ball-racket impact conditions, the difference in elbow loading for a topspin and slice one-handed backhand groundstroke is relatively small. In this study, the relatively small differences in elbow loading may be due to comparable angle-time histories at the wrist and elbow joints with the major kinematic differences occurring at the shoulder. Using a subject-specific angle-driven computer model combined with a forward dynamics, equipment-specific computer model of tennis ball-racket impacts allows peak internal loading, net impulse, and shock due to ball-racket impact to be calculated which would not otherwise be possible without impractical invasive techniques. This study provides a basis for further investigation of the factors that may increase elbow loading during tennis strokes.  相似文献   

Bowling ball dynamics revealed by miniature wireless MEMS inertial measurement unit   总被引：1，自引：1，他引：0  

Kevin King  N. C. Perkins  Hugh Churchill  Ryan McGinnis  Ryan Doss  Ron Hickland 《Sports Engineering》2011,13(2):95-104

This paper presents a novel sensor technology to deduce the dynamics of a bowling ball. The sensor, a miniature wireless inertial measurement unit (IMU), incorporates MEMS accelerometers and angular rate gyros, a microcontroller, a low power RF transceiver, and a rechargeable battery. When embedded in a bowling ball, the IMU transmits the acceleration and angular velocity data that define the dynamics of the ball starting with the bowler’s delivery and its motion in the lane. Example results from professional bowlers illustrate how this technology can be used to assess bowler skill and ball performance. For instance, the IMU accurately measures the spin dynamics of the ball which are crucial to develop the ball “hook.” An analysis of ball dynamics in the lane is distilled to a measurable “hook potential” metric for further assessing bowler skill. Finally, the sensor presented herein is believed to be the world’s smallest, wireless IMU. This highly miniaturized and wireless design will enable parallel training systems for many sports, including basketball, baseball, crew, cricket, golf, fly fishing, soccer, softball, tennis, rowing, among others.  相似文献   

Why Is This So Hard?: Ideologies of Endangerment,Passive Language Learning Approaches,and Ojibwe in the United States     

Kendall A. King  Mary Hermes 《Journal of Language, Identity & Education》2014,13(4):268-282

This paper describes 3 language learning approaches common in many urban and rural Ojibwe communities, as well as the ideologies of endangerment that drive and sustain them. Drawing from collaborative language revitalization work with teachers, learners, and community leaders, we analyze some of the teaching and learning practices that lead to the common mismatch between language learner goals and expectations, on the one hand, and the outcomes of language learning, on the other. We outline how these 3 approaches to language learning relate to cultural identities and place-based notions of authenticity as well as to current findings in the field of second language acquisition. We then profile 2 speakers who have learned Ojibwe successfully as adults to illustrate how their success was possible largely because they were able to engage with the Ojibwe language in interactive ways that run counter to common language learning approaches. We suggest that for language revitalization efforts, and individual learners, to experience higher levels of success, greater attention needs to be paid to how ideologies of endangerment impact language learning approaches.  相似文献   

Future Sex Educator Perceptions of Rural Versus Urban Instruction: A Case for Community-Centered Sexual Health Education     

Christina L. Jones  Robin E. Jensen  Abigail Selzer King 《American journal of sexuality education》2014,9(4):464-484

Instructors of sexual health courses in rural areas face unique challenges as they are often forced to use school-based prevention curricula field-tested in urban areas. Research has yet to consider what future sex educators’ regional expectations are for their profession and how those expectations might have an impact on the classroom. Drawing from interviews with 26 sex-educators-in-training, we find that future educators tended to expect that rural communities would be less diverse, more conservative, and less informed about sexual health matters, even though research demonstrates that today's rural communities inconsistently align with those perceptions.  相似文献   

Implementing VuFind: A Public Library Improves Electronic Search Quality and Saves Searcher Time     

Maria K. Burchill  Nathaniel Rasmussen 《Public Library Quarterly》2014,33(1):76-82

Web-scale discovery services (WSDs) are a widespread phenomenon sweeping university libraries across the world. In this article the authors discuss this trend and their experience working on a test server with the open source discovery layer VuFind. Developed by Demian Katz of Villanova University, VuFind’s potential to index not only the library’s catalog but also proprietary databases through the integration of application program interfaces (APIs) offers public libraries the opportunity to develop a seamless website-to-catalog experience, thereby building a true virtual branch for their patrons.  相似文献   

A COMPARISON OF FACTORS INFLUENCING ISSUE DIVERSITY IN THE U.S. AND TAIWAN     

Wanta  Wayne; King  Pu-tsung; McCombs  Maxwell E. 《Int. Journal of Public Opinion Research》1995,7(4):353-365

The study extends agenda-setting research by examining issuediversity as a consequence of media exposure. Results from twosurveys—one conducted in the United States, the otherin Taiwan—illustrate differences in the cultures of thetwo samples. In general, older individuals who find low utilityin advertising information but who read a variety of newspapersand feel a strong civic duty to keep informed believe thereare many important issues facing the United States. Younger,highly educated individuals who have a high interest in politicalnews and who read a variety of newspapers believe there aremany important issues facing Taiwan.  相似文献   

Demand for and productivity analysis of Turkish public theater   总被引：1，自引：0，他引：1  

Sacit Hadi Akdede  John T. King 《Journal of Cultural Economics》2006,30(3):219-231

We estimate a demand function for live theater provided by the General Directorate of State Theaters in Turkey. We show that demand is more elastic in less developed cities, that attendance is not significantly affected by various qualitative variables, and that the government's practice of offering free passes to government officials is an ineffective way of increasing paid attendance. Comedies and musicals both show significantly higher attendance. Having a Turkish author does not significantly affect attendance. Having a known author significantly increases attendance for more developed cities but not for less developed cities. Being the opening season significantly reduces attendance in less developed cities but has no effect in more developed cities. We also present evidence of inefficiency in state theaters in Turkey through a performance of plays equation in which we evaluate the determinants of the number of performances per play.  相似文献   

Educational Transfer in Kenya and Tanzania     

Kenneth King 《Compare》1983,13(1):81-87

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Canadian Health Libraries Association Annual Conference,June 1986, Montreal     

T. A. King 《Health information and libraries journal》1987,4(1):39-40

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Media Management Journal     

William L. King 《TechTrends》1988,33(6):32-37

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