On the acoustic signature of golf ball impact     

Shannon K  Axe JD 《Journal of sports sciences》2002,20(8):629-633

In this paper, we present results on the measurement and analysis of the sound that is produced by the sharp impact loading of a golf ball by a flat massive object (e.g. the face of a golf club). We discuss: (a) the motivation for such a study; (b) some necessary background information on how golf balls vibrate; (c) the techniques used to acquire and analyse the data; and (d) an analysis of the sound made by dropping balls on a smooth, massive concrete target surface. These results establish a simple method for rapid and non-destructive measurement of the effective high-frequency elastic shear moduli of balls and ball cores.  相似文献   

Interaction of wrestling shoe and competition surface: effects on coefficient of friction with implications for injury   总被引：1，自引：0，他引：1  

Newton R  Doan B  Meese M  Conroy B  Black K  Sebstianelli W  Kramer W 《Sports biomechanics / International Society of Biomechanics in Sports》2002,1(2):157-166

The purpose of this study was to determine whether there is a significant difference in the co-efficient of friction (Fc) between old versus new wrestling shoes and mats and to investigate the effect of perspiration. Fc was measured by dragging a weighted shoe over a wrestling mat surface and measuring the vertical and horizontal forces produced. Three different shoe conditions were assessed over two mat types for both wet and dry conditions for a total of 12 conditions. To simulate the wet condition, saline solution was smeared over the surface of the mat. There was a significant effect of shoe, mat, and wet/dry conditions. In addition, significant interactions of shoe by mat, shoe by dry/wet, and mat by dry/wet were observed. Overall, Fc was 36% higher for the new wrestling mat compared to the old wrestling mat. Application of the saline solution reduced Fc by 14% compared to the dry condition. Comparison of the mean Fc for all three shoe types revealed the Fc for the older design shoe was 23% to 28% lower than the brand new shoe and the worn newer design, respectively. A high Fc, such as in the new mat/new shoe combination, has the potential to increase the risk of knee and ankle injuries by fixing the foot more securely to the ground.  相似文献   

Leisure time physical activity in Australian women: relationship with well being and symptoms   总被引：5，自引：0，他引：5  

Brown WJ  Mishra G  Lee C  Bauman A 《Research quarterly for exercise and sport》2000,71(3):206-216

This paper explores the association between moderate levels of physical activity (PA) and health benefits in well being and symptoms such as tiredness, back pain, and constipation. Participants in the Australian Longitudinal Study on Women's Health, 14,502 young women (ages 18-23 years), 13,609 middle-age women (45-50 years), and 11,421 older women (ages 70-75 years), answered questions about vigorous and less vigorous exercise (used to determine a physical activity score), well being (SF-36), symptoms, and medical conditions. There were significant associations between the PA score and SF-36 in each cohort. Odds ratios (OR) for a range of symptoms and conditions were lower for women who reported low to moderate activity than for sedentary women, for example, for young women or for constipation = 0.76 (CI, 0.65-0.89), for middle-age women or for tiredness = 0.70 (0.63-0.78). There was no threshold of PA at which health benefits increased significantly. Although cross-sectional, the findings suggest that low-to-moderate levels of exercise are associated with a range of health benefits for women of all ages. These preliminary findings will be followed up during the longitudinal study.  相似文献   

POLLING AS A MEANS TOWARD PRESIDENTIAL AUTONOMY: EMIL HURJA, HADLEY CANTRIL AND THE ROOSEVELT ADMINISTRATION     

Eisinger  Robert M.; Brown  Jeremy 《Int. Journal of Public Opinion Research》1998,10(3):237-256

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The Employment of New Full-Time Community College Faculty Members     

James L. Brown 《Clearing house (Menasha, Wis.)》2013,86(8):356-357

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The Problem of Worship Among College Students ∗     

Kenneth Irving Brown 《Religious education (Chicago, Ill.)》2013,108(9):843-848

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Understanding conceptual innovation in science     

Harold I. Brown 《Metascience》2010,19(2):273-276

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One third cherokee: Problem solving,teaching, and intuition     

Stephen I. Brown  Gerald R. Rising 《Educational Studies in Mathematics》1978,9(4):391-409

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Modeling of Star-shaped and Parallel-wire Carrier Distribution Systems     

C. Yeh  F. Manshadi  G. Mariki  W.P. Brown 《Journal of The Franklin Institute》1978,305(2):67-78

It is often desirable to represent carrier distribution systems by networks so that analysis can be made to predict the behavior of these systems. Modeling of two canonical carrier distribution systems, the star-shaped system and the parallel-wire system by networks was carried out in this paper. The representation is given in terms of lumped parameters when the lengths of the carrier lines are short and it is given in terms of lumped and distributed parameters when the lengths of the carrier lines are long.  相似文献   

Managing governance     

Gavin Brown 《Minerva》2007,45(4):499-503

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