质点几何定理证明的机器实现

本文针对质点法生成的目标关系式的过程不简明,缺少明显几何意义的问题,提出了一种具有较高可读性算法的几何定理证明器MMP.首先,直接从消点公式推导目标关系式,该方法不再使用质点坐标而直接对质点进行运算;其次,利用三个模块架构证明器,彤成了具有完全性的消点过程;最后,利用待定系数法判定结论语句.由于可以对点直接进行运算,该证明器的消点过程比原有质点法具有明显的几何意义和较高运算效率.     

单调类定理的详细证明

在大多数测度论教材中,单调类定理的证明过程过于简洁,使得有的初学者在学习该定理时觉得十分困难,往往要经过很长的时间才能理解该定理。本文给出了该定理的详细证明,旨在帮助初学者快速掌握该定理,更快更好地学习测度论。     

勇敢者的证明

这是一个球探的故事。他不为权势所压．勇敢地做自己。然后在篮球之外的又一段历程中,实现了真正的人生价值。     

理光的证明

4月19日,苏州,第8届理光杯决赛,古力九段对邱峻八段。这是一场意志的对决。     

反复踢球器的制作

近期在准备一堂足球脚内侧踢地滚球技术的优质课,面对一群从未接触过足球的学生,如何上好一节既新颖、有趣,又能促进学生练习密度和强度的优质课,着实让我犯难。面对困难笔者不断开动脑筋大胆尝试,制作出"反复踢球器",有效地提高练习密度和强度,促使学生在较短的时     

关于一个重要极限的两种证明方法

本文对重要极限limn→∞(1+1/n)n=e的存在性进行了探讨,分别利用两个不等式结合单调有界定理给出了两种简洁的证法.     

篇章修辞的语义构式及衔接连贯

研究修辞学,不仅要研究字与句,也要研究章与篇,更要研究篇章中的言语风格。本文以篇章修辞为出发点,阐述了语义在篇章修辞中的重要性,它是篇章修辞的认知基础,同时明确了语义的特征。衔接连贯作为篇章修辞中一个核心结构特色,具有不同的表征形式,包括比喻、对比和排比。     

我们应该如何证明自己的存在？

前不久,埃及千年神庙出现“到此一游”一事,引发国人热议。事后得知,“肇事者”是南京一初中生,这位闯了祸的孩子立时成了千夫所指。作为一个中国人,笔者在得知此事时也觉得很没面子一一丢人怎么能丢到国外呢？事后冷静下来想想,其实出现这种状况,并非偶然,这件事其实给我们一个提醒,我们应该如何证明自己的价值与存在？事实上,从古至今,人人都有证明自己的存在与价值的本能,只是各人表现的方式不同罢了’“到此一游”或许也算是普通人的一种不太高雅的弱弱的表达而已。     

围棋对杀中公气归属的证明（外一篇）

问题的提 出有公气的对杀中,公气的归属显得极为重要,只有知道公气是属于双方还是属于某一方时,才能精确地计算出对杀双方的气数。而公气的归属,历来是一个知其然而不知其所以然的问题,围棋教材只会讲到“双方无眼或同眼位对杀时,公气是属于双方的;一方有眼一方无眼对杀时,公气是属于有眼方的;大眼和小眼对杀时,公气是属于大眼方的”,     

冰球运动视频资源管理的语义索引与检索方法探析

冰球运动视频资源是现代冰球运动技战术研究的重要组成部分,为克服传统冰球运动视频资源管理方法的局限性,一个解决方案是使视频资源管理系统具备语义搜索和过滤能力。为达到高效索引和检索的目的,进行了冰球运动视频资源的信息元素语义化分析,并初步提出冰球运动视频资源管理系统的语义索引结构设计方案,为建立专业化视频资源管理系统提供技术与方法参考。     

积极实施“人人运动计划” 开创全民健身新局面

为了加强今年上海市的全民健身工作 ,本文提出了大力推进“人人运动计划” ,开创健身活动新局面的一整套工作思路。     

Estimating VO2max Using a Personalized Step Test

The purpose of this study was to develop a step test with a personalized step rate and step height to predict cardiorespiratory fitness in 80 college-aged males and females using the self-reported perceived functional ability scale and data collected during the step test. Multiple linear regression analysis yielded a model (R = 0.90, SEE = 3.43 mL·kg^?1·min^?1) that included gender, body mass, perceived functional ability, step rate, and recovery heart rate. Based on the standardized β-weights, gender explained the largest proportion of variance in VO₂max values followed by perceived functional ability. The cross validation predicted residual sum of squares statistics show minimal shrinkage (R_PRESS = 0.88, SEE_PRESS = 3.57 mL·kg^?1·min^?1) in the accuracy of the regression model. This study provides a model to predict VO₂max from non-exercise data and data collected during an individualized multistage step test that is accurate, time-efficient, and easy to administer.     

论使用兴奋剂已经成为政治问题

兴奋剂的使用,严重地破坏着奥林匹克理想和奥运公平竞赛原则,成为奥运发展的大敌之一,国际奥委会正与之进行着坚决的斗争。兴奋剂的使用在我国也是一股潜在的暗流,我们也与之进行着卓有成效的坚决斗争。但,由于种种原因,仍然屡戒不止,屡禁不绝,甚至发展到近乎猖狂的程度(当然只是某些项目),已经成为一个有损我国形象的政治问题,必须认真提高政治认识,痛下决心,予以从严根治。     

Using a situation awareness approach to determine decision-making behaviour in squash

Situation awareness (SA) refers to the awareness of all relevant sources of information, an ability to synthesise this information using domain knowledge gained from past experiences and the ability to physically respond to a situation. Expert-novice differences have been widely reported in decision-making in complex situations although determining the small differences in expert behaviour are more elusive. This study considered how expert squash players use SA to decide on what shot to play. Matches at the 2010 (n = 14) and 2011 (n = 27) Rowe British Grand Prix were recorded and processed using Tracker software. Shot type, ball location, players’ positions on court and movement parameters between the time an opponent played a shot prior to the player’s shot to the time of the opponent’s following shot were captured 25 times per second. Six SA clusters were named to relate to the outcome of a shot ranging from a defensive shot played under pressure to create time to an attempted winner played under no pressure with the opponent out of position. This new methodology found fine-grained SA differences in expert behaviour, even for the same shot type played from the same court area, beyond the usual expert-novice differences.     

Using accelerometry to quantify deceleration during a high-intensity soccer turning manoeuvre

Abstract

The mechanics of cutting movements have been investigated extensively, but few studies have considered the rapid deceleration phase prior to turning which has been linked to muscle damage. This study used accelerometry to examine the influence of turning intensity on the last three steps of a severe turn.

Ten soccer players performed 135° “V” cuts at five different intensities. Resultant decelerations were recorded from a trunk-mounted tri-axial accelerometer. Lower limb kinematics and ground reaction forces (GRF) from the pivot foot-ground contact (FGC) were also monitored.

Average peak trunk decelerations were larger at the two preceding steps (4.37 ± 0.12 g and 4.58 ± 0.11 g) compared to the PIVOT step (4.10 ± 0.09 g). Larger peak joint flexion angular velocities were observed at PRE step (ankle: 367 ± 192 deg.s^?1; knee 493 ± 252 deg.s^?1) compared to PIVOT step (ankle 255 ± 183 deg.s^?1; knee 377 ± 229 deg.s^?1). Turn intensity did not influence peak GRF at PIVOT step.

This study highlights the importance of steps prior to turning and their high-frequency loading characteristics. It is suggested that investigations of lower limb loading during turning should include this deceleration phase and not focus solely on pivot FGC.     

Comparing Numerical Methods to Estimate Vertical Jump Height Using a Force Platform

ABSTRACT

Males (n = 29) and females (n = 34) performed vertical jumps. Jump height was estimated from force platform data using five numerical methods and compared using intraclass correlation (ρ), and linear and rank regression standard error of estimate (SEE). Take-off velocity plus center of mass height at take-off and mechanical work methods were identical (ρ = 1.000) with small linear (SEE < 0.0001 cm) and rank order (SEE = 0) error. Integrating acceleration to displacement was nearly identical (ρ > 0.999), with small linear (SEE = 0.1 cm) and rank order (SEE < 1) errors compared to the above methods. Take-off velocity (ρ = 0.517) and flight time (ρ = 0.573) estimates were less than all other methods and had large linear (SEE ≥ 2.1 cm) and rank order (SEE > 4) errors. Take-off velocity and flight time methods should be avoided due to systematic and random error.     

Revisiting the Development of Time Sharing Using a Dual Motor Task Performance

Abstract

The purpose of the study was to investigate the effect of a 2-min. isometric exercise training program on force and fatigue in a skeletal muscle. The subjects (N=60) were divided into two equal groups, control and experimental. The control group was tested twice, once at the beginning of the experiment and again after 20 days. The subjects in the experimental group were tested before embarked on a 20-day period of isometric training. held the tension for 2 min. in the morning and again in the afternoon. Periodic tests were on the 5th, 10th, 15th, and 20th days. Large gains of initial strength were recorded on the 5th day. Isometric training continued beyond five days produced no significant gains in initial strength althoughe was a significant increase in isometric endurance. Isometric exercise continued longer than 15 days resulted in a significant decrease in initial strength and isometric endurance.     

运用心理训练克服跨栏中的不良心理

在跨栏训练和比赛中,往往会产生一些不良的心理反映。通过心理训练的不同方法,使学生掌握调节自己心理状态的各种方法,以便在训练和比赛中取得更好的成绩。在以往的教学与训练中,教师更多的注重身体素质和技术动作的训练,往往忽视了对学生的心理训练,以致于在比赛时不能发挥最佳水平。所以心理训练对学习掌握运动技术和提高跨栏成绩具有重要作用。     

Cross-Validation of a Quarter-Mile Walk Test Using Two VO2 max Regression Models

This study was conducted to evaluate the accuracy of 2 regression models (Dolgener, Hensley, Marsh, & Fjelstul, 1994; Kline et al., 1987) in the prediction of VO_{2 max} College-age men and women (N = 37) performed, in a counter-balanced order, a 1/4-mile walk test, a 1-mile walk test, followed by a maximal graded exercise test. For both walking tests, participants were instructed to self-select a fast (but less than maximal) steady exercise pace. For the 1-mile walk, the applicable data (e.g., age, gender, body weight, elapsed 1-mile exercise time, and ending exercise heart rate) were inserted into the Dolgener et al. (1994) equation and Kline et al. equation, respectively, to predict VO_{2 max} A similar approach was taken to predict VO_{2 max} for the 1/4-mile walk, except that elapsed exercise times were first multiplied by 4 to get 1-mile walk equivalents (because both equations are designed to predict VO_{2 max} based on 1-mile data). The Kline et al. equation provided relatively accurate estimates of observed VO_{2 max} values with mean residuals ranging from -0.36 to + 1.59 ml kg^-1; min-1 and correlations ranging from .81 to .84. The percentage of predicted and observed VO_{2 max} values within 4.5 ml kg^-1; min^-1; ranged from 67.6% to 75.7%. The Dolgener et al. (1994) equation, on the other hand, underpredicted observed VO_{2 max} values with mean residuals ranging from -5.67 to -6.83 ml kg^-11; min^-1; and correlations ranging from .84 to .85. The percentage of predicted and observed VO_{2 max} values within 4.5 ml kg^-1; min^-1; ranged from 18.9% to 43.2%. The results of this study provide evidence that the 1/4-mile walk predicts VO_{2 max} with about the same accuracy as the 1-mile walk.