Lightweight design optimization of a Bow Riser in Olympic Archery applying evolutionary computing

Recurve bows that are used in competitions like the Olympic Games are high-technology products. Good risers are lightweight but retain a high stiffness. The aim of this study was to design a riser with a stiffness comparable to that of the lightest riser currently used by the archers of the German National Archery Team, but with a considerably reduced weight. We computed the loads that are applied to a riser of a drawn recurve bow (the RADIAN model used by the German team) and created a 3-D solid CAD model of a riser with 24 variable parameters. We used evolutionary computing to optimize the 24 parameters of the model according to these criteria. We selected the most optimal riser out of the 1650 CAD models generated, manufactured it, and had it tested by three archers of the German National Archery Team. The mass of our manufactured riser is 871g, which is 243g or 22% less mass than the RADIAN riser.     

Effects of starting score-line,game location,and quality of opposition in basketball quarter score

Abstract

In several team sports, the game starting score-line may be understood as a measure of performance accomplishment and hence might have an effect on players' subsequent efforts. The aim of this study was to identify the effect of the starting score-line, game location, and quality of opposition on basketball game quarter final score. The sample comprised 504 game quarters from the Spanish Basketball Professional League and these were classified as balanced (difference in scores equal of 8 points or less, n=194) and unbalanced (difference in scores of more than 8 points, n=310) using k-means cluster procedures. The effects of the predictor variables on game quarter outcome (difference between points scored and points received) in the whole game and in the second, third, and fourth game quarters were analysed using linear regression analysis. The starting game quarter score-line was only significant in unbalanced situations with very similar effects among different game quarters. The greater the difference in accumulated score at the beginning of each quarter, the more points recovered by the teams who were losing. A small effect from the quality of the opponent was found in the second and third quarters, whereas game location only had an effect when analysing the whole game and second quarter using balanced and unbalanced game quarters combined.     

Martial arts striking hand peak acceleration,accuracy and consistency

Abstract

The goal of this paper was to investigate the possible trade-off between peak hand acceleration and accuracy and consistency of hand strikes performed by martial artists of different training experiences. Ten male martial artists with training experience ranging from one to nine years volunteered to participate in the experiment. Each participant performed 12 maximum effort goal-directed strikes. Hand acceleration during the strikes was obtained using a tri-axial accelerometer block. A pressure sensor matrix was used to determine the accuracy and consistency of the strikes. Accuracy was estimated by the radial distance between the centroid of each subject's 12 strikes and the target, whereas consistency was estimated by the square root of the 12 strikes mean squared distance from their centroid. We found that training experience was significantly correlated to hand peak acceleration prior to impact (r ²=0.456, p =0.032) and accuracy (r ²=0. 621, p=0.012). These correlations suggest that more experienced participants exhibited higher hand peak accelerations and at the same time were more accurate. Training experience, however, was not correlated to consistency (r ²=0.085, p=0.413). Overall, our results suggest that martial arts training may lead practitioners to achieve higher striking hand accelerations with better accuracy and no change in striking consistency.     

高校田径运动的人文内涵及其多样化发展特征的研究

高校在注重知识学习、积累的同时更应注重学生素质、体质的提高,在高校进行的各项体育运动中田径运动是基础,它对学生不仅仅具有健身价值和竞技价值,而且田径运动中所蕴含的人文价值对学生具有重大的影响。     

论现代网球运动的贵族内涵

采用文献资料法从网球运动的起源背景入手,研究了古式网球运动的贵族特质,认为古式网球的贵族特质主要体现在古式网球是贵族阶层的特权运动,古式网球的花费昂贵,古式网球的参与者具有高贵、优雅的气质;并分析了当代网球虽然已经不是当权阶层的特权,其花费也不再昂贵,但依然具有强烈的贵族气质：现代网球体现了人们高贵的生活态度,反映了参与者高贵的个性心理特征及气质,体现了人们高贵、文明、高雅的社交礼仪,展现了人们公平公正、诚实守信的高尚品质,展示了人们的高智商水平。     

江苏民俗传统体育发展及其对新农村体育文化建设的作用——以泰州市为例

随着我国经济的不断发展,人民生活水平的不断提高,人们对身心健康有了强烈愿望,开始自觉地进行体育锻炼。本文采用文献资料、逻辑分析等研究方法对泰州市民俗传统体育的内涵及在新农村体育文化建设的价值进行分析,挖掘和利用长期积淀的民俗传统体育文化资源,对弘扬和发展农村优秀体育文化传统,提高农村现代化物质与精神生活水平,树立社会主义新农民形象,推动新农村建设健康发展提供理论参考。     

浅析中韩体育文化差异

本文在查阅大量文献资料的同时,走访民众关于体育文化的不同理解,主要从民众参与体育的意识、体育行为、体育诉求分析中韩两国体育文化存在的差异;在一定的历史时期有助于我国沉积优良的体育文化成果,推进体育事业的进一步发展。     

体育舞蹈在高尔夫技术教学中的应用研究

作为一项新兴的运动项目,高尔夫技术教学的方法和手段研究不足。为使初学者尽快掌握高尔夫技术关键点,提出了在高尔夫技术教学中引入体育舞蹈的观点。认为将体育舞蹈渗入到高尔夫技术教学过程中的各个环节,能帮助学生建立核心力量观念,体会恰当的重心转移,学会控制动作节奏,还能激发学生的学习兴趣。运用此教法进行的教学实验结果也表明,实验组学生的专项技能测评的平均成绩明显优于对照组,且该差异性具有高度显著性(P<0.01),表明此教学法具有较高的应用与推广价值。     

阳光体育运动下大学生体质健康的现状研究

本文采用文献资料法、问卷调查法、数理统计法等研究方法,对河南省全日制大学生阳光体育运动下体质健康的调查分析。结果显示:大学生总体体质健康状况良好,但是优秀率相对较低,女生相对男生体质相对较好;男生握力体重指数优秀范围的人数较高,前臂和手部肌肉的力量素质良好;女大学生生坐位体前屈优秀率较高,腰部柔韧性素质良好等。