Optimal sampling frequency in recording of resistance training exercises     

Paolo Bardella  Irene Carrasquilla García  Marco Pozzo  Julio Tous-Fajardo  Eduardo Saez de Villareal 《Sports biomechanics / International Society of Biomechanics in Sports》2017,16(1):102-114

The purpose of this study was to analyse the raw lifting speed collected during four different resistance training exercises to assess the optimal sampling frequency. Eight physically active participants performed sets of Squat Jumps, Countermovement Jumps, Squats and Bench Presses at a maximal lifting speed. A linear encoder was used to measure the instantaneous speed at a 200 Hz sampling rate. Subsequently, the power spectrum of the signal was computed by evaluating its Discrete Fourier Transform. The sampling frequency needed to reconstruct the signals with an error of less than 0.1% was f_99.9 = 11.615 ± 2.680 Hz for the exercise exhibiting the largest bandwidth, with the absolute highest individual value being 17.467 Hz. There was no difference between sets in any of the exercises. Using the closest integer sampling frequency value (25 Hz) yielded a reconstruction of the signal up to 99.975 ± 0.025% of its total in the worst case. In conclusion, a sampling rate of 25 Hz or above is more than adequate to record raw speed data and compute power during resistance training exercises, even under the most extreme circumstances during explosive exercises. Higher sampling frequencies provide no increase in the recording precision and may instead have adverse effects on the overall data quality.  相似文献   

我国体育产业发展现状、问题与对策建议     

荆林波 《南京体育学院学报(社会科学版)》2016,(4):1-10

体育产业化是世界体育强国发展的普遍规律，作为朝阳产业，它的发展程度是衡量一个国家体育经济与体育文化发展水平的重要标志。文中通过文献资料整理，对体育产业的概念进行了界定和阐释，以全球体育产业为视角，对美国、英国、德国和澳大利亚的发展状况进行对比分析，梳理和归纳我国体育产业发展特征，剖析我国体育产业存在的问题，以“十三五”国家发展战略为契机，提出了一系列促进我国体育产业整体发展水平的对策与建议，以期为我国实现体育强国梦提供一定的理论参考。  相似文献   

陕甘宁边区体育发展的历史价值及其对当代体育发展的启迪     

翟小巧 《南京体育学院学报(社会科学版)》2016,(4):44-53

采用文献资料法、逻辑演绎法等方法分析边区体育发展的历史动因和历史价值，目的在于揭示其发展与繁荣的历史必然性，准确把握当代体育发展的历史逻辑，并从中获得历史借鉴和启示。陕甘宁边区体育的发展与繁荣，抗日战争与民族意识的觉醒为其提供了精神动力，领导身体力行与专业组织的成立为其提供了组织保障，自己动手丰衣足食的方针与大生产运动为其提供了物质基础，专门的培训机构与体育人才的培养为其提供了技术支持。陕甘宁边区体育具有军事化、大众化和常态化特点，其历史价值在于：增强了军民的体质，提高了部队战斗力；促进了边区人民的空前团结，凝聚了民族力量；为新中国体育的发展开辟了新的路径，积累了宝贵的经验，提供了人才支持和技术基础。陕甘宁边区体育的发展启示我们：当代体育的发展不仅需要崇高的理想来引领、健全的组织来领导、专业的人才来支撑、先进的文化来保障，而且必须具有鲜明的服务“健康中国”“美丽中国”的时代主题和服务服务于广大普罗大众的价值取向。  相似文献   

Factors associated with concussion-symptom knowledge and attitudes toward concussion care seeking in a national survey of parents of middle-school children in the US     

Zachary Y. Kerr  Aliza K. Nedimyer  Melissa C. Kay  Avinash Chandran  Paula Gildner  K. Hunter Byrd  Juliet K. Haarbauer-Krupa  Johna K. Register-Mihalik 《运动与健康科学(英文)》2021,10(2):113

BackgroundDeveloping appropriate concussion prevention and management paradigms in middle school (MS) settings requires understanding parents’ general levels of concussion-related knowledge and attitudes. This study examined factors associated with concussion-symptom knowledge and care-seeking attitudes among parents of MS children (aged 10–15 years).MethodsA panel of 1224 randomly selected U.S. residents, aged ≥ 18 years and identifying as parents of MS children, completed an online questionnaire capturing parental and child characteristics. The parents’ concussion-symptom knowledge was measured using 25 questions, with possible answers being “yes”, “maybe”, and “no”. Correct answers earned 2 points, “maybe” answers earned 1 point, and incorrect answers earned 0 point (range: 0–50; higher scores = better knowledge). Concussion care-seeking attitudes were also collected using five 7-point scale items (range: 5–35; higher scores = more positive attitudes). Multivariable ordinal logistic regression models identified predictors of higher scores. Models met proportional odds assumptions. Adjusted odds ratios (aORs) with 95% confidence intervals (95%CIs) (excluding 1.00) were deemed statistically significant.ResultsMedian scores were 39 (interquartile range: 32–44) for symptom knowledge and 32 (interquartile range: 28–35) for care-seeking attitude. In multivariable models, odds of better symptom knowledge were higher in women vs. men (aOR = 2.28; 95%CI: 1.71–3.05), white/non-Hispanics vs. other racial or ethnic groups (aOR = 1.88; 95%CI: 1.42–2.49), higher parental age (10-year-increase aOR = 1.47; 95%CI: 1.26–1.71), and greater competitiveness (10%-scale-increase aOR = 1.24; 95%CI: 1.13–1.36). Odds of more positive care-seeking attitudes were higher in white/non-Hispanics vs. other racial or ethnic groups (aOR = 1.45; 95%CI: 1.06–1.99) and in older parental age (10-year-increase aOR = 1.24; 95%CI: 1.05–1.47).ConclusionCharacteristics of middle school children''s parents (e.g., sex, race or ethnicity, age) are associated with their concussion-symptom knowledge and care-seeking attitudes. Parents’ variations in concussion knowledge and attitudes warrant tailored concussion education and prevention.  相似文献   

大型赛事赞助、网络关注度与企业市场价值--2018年俄罗斯世界杯中国赞助商实证研究     

付磊  蔡兴林 《体育科学》2020,(4):28-34

企业赞助大型体育赛事目的是为了提升企业的市场价值,针对多家中国企业赞助2018年俄罗斯世界杯的事件,用事件研究方法考察了企业签约赞助和开赛日2个阶段股票价格的异常收益波动,并用百度指数研究了网络关注度对异常收益的影响关系。研究发现,中国企业赞助俄罗斯世界杯,在签约事件窗口内企业获得正向的市场绩效,而在开赛日事件窗口内企业获得负向的市场绩效。百度指数与股票异常收益的关系,说明网络关注度对事件影响产生催化剂的作用。研究结果表明,企业赞助大型赛事需要注重短期和长期的效果,注意防止过度炒作,并要积极采用营销组合的手段扩大赞助带来的影响和收益。  相似文献   

对2019年中国电视剧研究的分析与反思     

金丹元  陈莎 《美育学刊》2020,11(2):47-54

2019年正值新中国成立70周年,我国电视剧创作出产了许多革命历史题材和现实主义电视剧佳作,同时网络剧也开始从边缘走向中心,成为观众喜闻乐见的电视剧形式。通过梳理、概括国内重要的学术期刊、报纸和会议论文中关于电视剧研究的文章,并从内容创作、美学价值、类型特点和女性塑造等几个方面进行解读,可以归纳出本年度电视剧研究的热点和焦点,同时也提出了对电视剧研究新动向的一些看法,以期为电视剧研究和创作提供借鉴。  相似文献   

电机学精品在线开放课程校企合作初探     

肖金凤  徐祖华  邓攀 《中国教育技术装备》2020,(4):50-52

工程教育专业认证背景下,电机学省级精品在线开放课程注重校企合作,收集丰富的生产现场教学资源,聘请企业专家录制教学视频,开展网上讨论、网上直播课等。下阶段校企合作重点是编写理论和实践教材、共建电机科技活动实训室、企业专家指导网上PBL项目、指导学生选取企业真题申报大创项目。  相似文献   

Experiences of Danish Business Expatriates in Russia: Power Distance in Organizational Communication     

Elena V. Chudnovskaya  Laura S. O’Hara 《Journal of Intercultural Communication Research》2016,45(4):261-281

Rapid globalization of business processes stimulates many companies to dispatch their employees – business expatriates – on overseas assignments. Russia differs markedly from many other cultures in terms of specific communication norms and rules. Understanding such differences in organizational life is crucial for the success of business expatriates working there. This study employs in-depth interviews with eight Danish business expatriates who worked in Russia and examines the differences between the Danes and the Russians in terms of communication characteristics related to Hofstede’s cultural dimension power distance. This work enhances scholars’ empirical knowledge of power distance, which has rarely been investigated qualitatively.  相似文献   

复合式训练影响青少年下肢爆发力的meta分析     

翟华楠  周彤 《武汉体育学院学报》2020,54(10):65-71

目的：运用元分析的方法检验复合式训练对青少年下肢爆发力影响的干预效果，检验并提出最优的运动干预方案。方法：运用STATA 15.1和Review Manager 5.3对纳入的10篇文献和301名被试者通过设置抗阻类型、抗阻强度、间歇时间、训练频率和训练周期等5个调节变量进行亚组分析，采用固定效应模型进行整体效应、异质性、发表偏倚性检验。结果：（1）复合式训练对跳跃类运动表现的影响效应量d0.36，对短跑类运动表现的影响效应量d-0.51，两者达到中等效应且具有统计学意义；（2）本研究纳入的10篇文献异质性较低，间歇时间、训练频率和训练周期的对跳跃类和短跑类运动表现影响的效应量有一定差别。结论：（1）复合式训练能够显著提升青少年跳跃类和短跑类运动表现；（2）抗阻训练选择等张收缩、强度70%1RM以下、小于3分钟的间歇时间、在4~8周内选择每周1-2次的复合式训练能够对青少年运动表现有较好的提升；（3）围绕青少年人群开展的复合式训练较为缺乏，后续研究应加强理论与实践研究。  相似文献   

我国低碳航运产业价值链的结构乘数效应     

甘爱平  詹凌晨  真虹  张婕姝 《上海海事大学学报》2016,37(3):47-51

针对航运低碳投资支出巨大的问题，运用结构性乘数，对我国用于低碳航运产业价值链中的支出产生的乘数效应进行研究.由两部门计算的简单投资乘数为1.547 7，由四部门计算的投资乘数均值为1.293 1.从长期看，乘数效应反映出航运低碳产业的投资收益大于投资支出，对航运业低碳减排具有现实和经济意义.  相似文献