基于波束扫描的DBF天线方向图测试方法

DBF天线安装后,一般不具备可机械旋转的常规测试条件。研究DBF天线方向图的间接测试问题,提出一种基于波束扫描的测试方法,给出其测试原理和测试流程。针对波束宽度、副瓣水平和波束指向等天线主要参数,用仿真比对该方法与常规方法的测试结果和误差。在DBF天线方向图正常和异常两种情况下,两种方法可得到相近的仿真测试结果,证明间接测试方法的有效性。     

浅谈我国企业进行体育赞助存在的问题及应对措施

体育赞助已成为企业进行市场推广的有效工具之一,它有助于提升企业的形象和品牌知名度,直接给企业带来巨大的经济效益。本文首先分析了体育赞助会对我国企业的全面竞争带来利益,然后针对我国企业目前在体育赞助中存在的一些薄弱问题,提出了如何使我国企业有效进行体育赞助的一些应对措施。     

兰州市青少年体育舞蹈开展的现状调查与对策研究

随着体育舞蹈运动的逐渐普及,为了促进西部地区青少年体育舞蹈运动的开展,采用访谈、问卷、统计等方法,对兰州市青少年体育舞蹈开展的现状进行了分析与研究,针对教师专业水平较低,组织管理滞后,场地设施和比赛制度不完善等主要影响因素提出了对策。     

关于人类运动极限的哲学思考

北京奥运会上,博尔特以令人难以置信的速度打破了人类100 m世界纪录,又一次引发了关于人类运动极限的大讨论.在此背景下,在分析人类运动极限的两个相反观点基础上,认为:生理极限是人类运动极限有限论的理论基础;社会因素的时代性是人类运动极限无限论的理论基础;自然外力是制约运动极限的偶然性因素,只有在自然外力最大的基础上讨论人类运动极限才有实际意义;测不准原理决定了人们用数量方法预测人类运动极限的局限性;人类运动极限是有限性和无限性的统一.     

我国国民体质检测指标体系的变化研究

通过对近几十年来幼儿、学生、成人和老人组检测指标体系进行整理、研究,发现形态、机能和素质3类指标趋于稳定和合理,医学上的部分指标运用在学生的体质检测上,心理健康和社会适应方面的指标几乎没有。建议在幼儿组加入反应心理发育的测试指标（或量表）,在学生和成年人组加入心理健康和社会适应测试指标（或量表）,老年人群的测试应与健康检查结合在一起及尽快制定出70岁以上老年人群的测试指标。     

CUBA男子篮球运动员身体素质测试结果分析

运用问卷调查、定量测试等方法,对8支CUBA男子篮球运动员各项身体素质指标进行了测试。发现后卫、前锋、中锋不同位置队员在速度、柔韧和下肢力量的差异不具有显著性意义;仰卧起坐、弹跳和速度耐力三项中,三种位置队员间的差异都具有非常显著性意义;灵敏素质、一般耐力素质方面,各位置队员问的差异都具有显著性意义。     

动作协调与"爆发力"表现田径跳跃动作协调能力测量与评价方法研究

通过专家访谈与问卷调查,确定了6组12项动作指标作为协调能力测试行为样本。运用生物力学方法与人体运动的动力学方法,以相同动作冗余自由度的控制与不控制作为刺激变量,以动作爆发力表现水平的差值为因变量,通过对两组不同水平被试测验成绩的比较,对跳跃专项动作协调能力进行了定性与定量评价。     

体力活动测量方法研究进展

体力活动水平与健康之间存在着剂量反应,如何准确测量体力活动水平是研究人员关心的问题。本文综述了体力活动研究的几种主要方法:行为观察法,双标水法,间接热量测量法,心率法,运动传感器法,问卷法。双标水法被认为是人体能量消耗测量的金标准,间接热量测量法也经常被用来校正其他测量方法,但这两种方法很难在大规模人群中应用。运动传感器和问卷法是在大规模人群中应用比较多的两种方法。     

The dynamic control ratio at the equilibrium point (DCRe): introducing relative and absolute reliability scores

Analytical methods to assess thigh muscle balance need to provide reliable data to allow meaningful interpretation. However, reproducibility of the dynamic control ratio at the equilibrium point has not been evaluated yet. Therefore, the aim of this study was to compare relative and absolute reliability indices of its angle and moment values with conventional and functional hamstring–quadriceps ratios. Furthermore, effects of familiarisation and angular velocity on reproducibility were analysed. A number of 33 male volunteers participated in 3 identical test sessions. Peak moments (PMs) were determined unilaterally during maximum concentric and eccentric knee flexion (prone) and extension (supine position) at 0.53, 1.57 and 2.62 rad · s^–1. A repeated measure, ANOVA, confirmed systematic bias. Intra-class correlation coefficients and standard errors of measurement indicated relative and absolute reliability. Correlation coefficients were averaged over respective factors and tested for significant differences. All balance scores showed comparable low-to-moderate relative (<0.8–0.9) and good absolute reliability (<10%). Relative reproducibility of dynamic control equilibrium parameters augmented with increasing angular velocity, but not with familiarisation. At 2.62 rad · s^–1, high (moment: 0.906) to moderate (angle: 0.833) relative reliability scores with accordingly high absolute indices (4.9% and 6.4%) became apparent. Thus, the dynamic control equilibrium is an equivalent method for the reliable assessment of thigh muscle balance.     

Is a single question of the Global Physical Activity Questionnaire (GPAQ) valid for measuring sedentary behaviour in the Chilean population?

A study was conducted to assess the validity of the Global Physical Activity Questionnaire (GPAQ) for measuring sedentary behaviour (SB) in the Chilean adult population. About 217 adults (93/124 male/female, 43.8 ± 15.75 years) who were randomly selected during National Health Survey 2009–2010 completed the protocol. The participants wore an ActiGraph GT3X (AG) for 7 consecutive days and then completed the GPAQ (single-item question for measuring time spent sitting in a usual day). Validity was examined using Spearman’s correlation, mean bias and limits of agreement (LoA), with AG (vertical axis <100 counts · min^?1) as the reference standard for estimates of SB in bouts of 1 (AG1), 5 (AG5) and 10 (AG10) min. Agreement between the GPAQ and AG for classifying data into quartiles and tertiles was assessed with kappa method. The GPAQ showed fair correlation with AG1, AG5 and AG10 (range = 0.23–0.26), with large mean biases (range = ?293.9, ?76.12 min · day^?1). Agreement between the GPAQ and AG1, AG5 and AG10 was poor for categorising time spent in SB into tertiles and quartiles. The single question from the GPAQ has shown fair validity for measuring SB and poor ability for correctly classifying individuals into tertiles or quartiles of SB in a Chilean population.