A mathematical model for power output in rowing on an ergometer     

Scott?GordonEmail author 《Sports Engineering》2003,6(4):221-234

A mathematical model relating power output of rower to stroke rate on an ergometer (the Concept II Indoor Rower TM, Model C) is studied. The model is used to analyse the ergometer performance of a particular rower. It is determined that he can be more efficient (i.e. decrease power output while maintaining fixed velocity) by decreasing stroke rate, but at the expense of increasing force during the drive. It is also shown that he can be more efficient by increasing the drag factor (using higher vent setting) without increasing force. Dependence of power output on rowing style (the shape of the force curve) is also examined. It is shown that variation of force during the drive has little effect on efficiency, but efficiency is reduced by asymmetry of the force curve that favours the legs.  相似文献   

Index to Volume XLI     

Jean Bocock  Lewis Baston  Peter Scott  David Smith 《Minerva》2003,41(4):421-422

Other Index

Index to Volume XLI  相似文献   

Caution regarding exergames: a skill acquisition perspective     

Scott J. Pedersen  Paul D. Cooley  Vaughan J. Cruickshank 《Physical Education & Sport Pedagogy》2017,22(3):246-256

Background: The advent of technology use in physical education is upon us. But the implications of using exergames as a substitute for traditional physical education instruction for some students raise questions. Although exergames have the potential to increase energy expenditure and motivation in some children, it is less clear whether they can provide skill acquisition benefits that are similar to those found in traditional physical education.

Purpose: In a previous experiment from our laboratory, we found that deliberate practice can significantly reduce the planning time required for lateral arm movements. The purpose of this study was to determine if exergames can produce a similar effect, by reducing the processing time required for children to initiate arm movements to the contralateral and ipsilateral space.

Participants and setting: Thirty children (boys?=?15, girls?=?15), between the ages of 7 and 12 years, participated in a pre- and post-test each taking 30?min and one 30?min treatment session in a university laboratory.

Research design: A repeated measures design was employed to test the effects of deliberate laterality practice on processing speed. Children were randomly assigned (n?=?10) to either a Nintendo Wii tennis contralateral movement experimental group, Nintendo Wii bowling ipsilateral movement experimental group, or handheld video-game control group. Each child participated in one 30?min treatment session.

Data collection: Upper extremity choice reaction time (RT) was measured through 27 goal-directed aiming movements for each arm separately, during the pre-test and post-test. The stimulus–response trials occurred in three randomly presented directions (ipsilateral, contralateral, and midline).

Data analysis: A 3 (treatment group)?×?2 (age group)?×?2 (test)?×?3 (direction) mixed design analysis of variance with repeated measures on the last two factors was used to test for significant differences, with an alpha level set at 0.05.

Findings: There were no significant treatment effects on RT across all groups indicating that a short bout of exergame training was unsuccessful in improving lateral movement processing.

Conclusions: Deliberate laterality practice using exergames did not improve the motor processing speed of lateral arm movements in the same manner of traditional physical education as indicated by our previous research. Explanations as to why exergames do not exhibit the same positive transfer for skill acquisition as traditional physical education instruction are discussed within this paper.  相似文献   

Nutritional engineering,IV: From wartime situations to peacetime policy     

Henry C. Sherman 《Journal of The Franklin Institute》1944,238(5):319-324

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Repeated retention testing effects do not generalize to a contextual interference protocol     

Fairbrother JT  Shea JB  Marzilli TS 《Research quarterly for exercise and sport》2007,78(5):465-475

Three experiments examined repeated retention testing effects in a contextual interference (CI) protocol. Retention was assessed at 10 min and 24 hr following acquisition or at just 24-hr for the one-test conditions. Experiments 1 and 2 used speeded-response key-pressing tasks. Dependent measures were total time and errors. Experiment 3 used sequential-timing tasks. Dependent measures were absolute error and absolute constant error Results revealed CI effects in each experiment. Repeated retention testing effects were not found in Experiments 1 and 3. Experiment 2 revealed superior performance by the two-test condition compared to the one-test condition. This result was qualified by possible practice effects during the 10-min test. It was concluded that repeated retention testing does not present problems for most studies of CI.  相似文献   

An evaluation of three authoring-language software packages     

R. Scott Grabinger 《TechTrends》1985,30(4):20-23

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Meditations in Black: The Vietnam Veterans Memorial     

Grant F. Scott 《Journal of American culture (Malden, Mass. : 2003)》1990,13(3):37-40

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St. Paul,the man and the teacher     

C. Anderson Scott M.A. D.D. 《British Journal of Religious Education》1938,5(3):125-133

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Introduction: education policy analysis for a complex world: poststructural possibilities     

Kalervo N. Gulson  Amy Scott Metcalfe 《Critical Studies in Education》2015,56(1):1-4

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Culturally responsive computing: a theory revisited     

Kimberly A. Scott  Kimberly M. Sheridan  Kevin Clark 《Learning, Media and Technology》2015,40(4):412-436

Despite multiple efforts and considerable funding, historically marginalized groups (e.g., racial minorities and women) continue not to enter or persist in the most lucrative of fields – technology. Understanding the potency of culturally responsive teaching (CRT), some technology-enrichment programs modified CRP principles to establish a culturally responsive computing (CRC) experience for disenfranchised groups. We draw from our respective praxes developing two such initiatives and reconceptualize CRC as a heuristic. In this theoretical article, we offer a more nuanced vision of CRC considering intersectionality, innovations, and technosocial activism. Implications for the newly defined tenets consider programmatic, theoretical, and methodological concerns.  相似文献