Automated processes in tennis: Do left-handed players benefit from the tactical preferences of their opponents?

Abstract

Previous research on laterality in sport suggests an over-representation of left-handers in interactive sports such as tennis and cricket. These findings potentially reflect left-handers' advantage over their right-handed competitors in those sports. Although considered crucial for successful performance, the tactical component of their superiority has yet to be analysed. Two studies were conducted to test for a side bias in tennis players' tactical preferences. In the first study, 108 right- and left-handed players of varying skill watched rallies on a computer screen and had to indicate where they would place the ball in the opposing half. The results showed the tactical preference of players to place more balls on a left-handed opponent's mostly stronger forehand side compared with when faced with a right-hander. In the second study, 54 professional tennis matches involving right- and left-handers were analysed with respect to ball placement frequencies on the opponent's backhand side. Significantly fewer balls were hit to the backhand side of a left-handed opponent, thus replicating the findings of Study 1 in on-court situations. Both studies indicate players' preference to place shots to their right irrespective of their opponent's handedness. Findings support the assumption that left-handers might enjoy a strategic advantage in tennis.     

The Role of the Components of Knowledge of Results Information in Error Correction

Abstract

The purpose of this study was to determine the usefulness of the components of a knowledge of results (KR) statement for organizing response correction. Forty-eight subjects learned to move a handle to a criterion location on a linear positioning apparatus. Error direction and distance components of the KR statement were manipulated across four independent groups. Two 4 × 15 Analyses of Variances were calculated on absolute error (AE) and constant error (CE) scores. The groups main effect, trials main effect, and the interaction groups × trials effect were significant for both analyses. Groups receiving directional information were more accurate in error correction than was the distance only group. Manipulation of distance information also influenced error correction on the initial trials. The results were interpreted as an indication that the learner's initial error corrections are based on directional information and that the distance of the error information which initially lacks meaning interferes with initial response accuracy.     

二语习得中语言迁移的演化：从对比分析到中介语

语言迁移一直是第二语言习得和语言教学领域有争议的论题,它对二语习得和教学的影响已经是公认的事实。文章简要概述了对比分析、偏误分析和中介语理论中关于语言迁移研究对二语习得研究的贡献,分别指出其理论基础和研究中存在的局限,希望借此整理外语教师在二语习得理论上的思路,为二语习得教学和学习提供更好的理论依据和指导。     

韩国留学生汉语程度补语搭配的偏误分析

本文以教学过程中积累的韩国留学生的偏误为研究对象,利用偏误分析的理论,归纳出韩国留学生学习汉语程度补语时述语和补语搭配产生的偏误类型,从本体研究角度分析其原因,以期指导教学。     

A Note on Noncentrality Parameters for Contrast Tests in a One-Way Analysis of Variance

The noncentrality parameter for a contrast test in a one-way analysis of variance is based on the dot product of 2 vectors whose geometric meaning in a Euclidian space offers mnemonic hints about its constituents. Additionally, the noncentrality parameters for a set of orthogonal contrasts sum up to the noncentrality parameter for the omnibus F test. The author provides an example of Helmert contrasts to demonstrate the use of the noncentrality parameters in contrast tests.     

Integrating different tracking systems in football: multiple camera semi-automatic system,local position measurement and GPS technologies

Abstract

During the past decade substantial development of computer-aided tracking technology has occurred. Therefore, we aimed to provide calibration equations to allow the interchangeability of different tracking technologies used in soccer. Eighty-two highly trained soccer players (U14–U17) were monitored during training and one match. Player activity was collected simultaneously with a semi-automatic multiple-camera (Prozone), local position measurement (LPM) technology (Inmotio) and two global positioning systems (GPSports and VX). Data were analysed with respect to three different field dimensions (small, <30 m² to full-pitch, match). Variables provided by the systems were compared, and calibration equations (linear regression models) between each system were calculated for each field dimension. Most metrics differed between the 4 systems with the magnitude of the differences dependant on both pitch size and the variable of interest. Trivial-to-small between-system differences in total distance were noted. However, high-intensity running distance (>14.4 km · h^?1) was slightly-to-moderately greater when tracked with Prozone, and accelerations, small-to-very largely greater with LPM. For most of the equations, the typical error of the estimate was of a moderate magnitude. Interchangeability of the different tracking systems is possible with the provided equations, but care is required given their moderate typical error of the estimate.     

北方体育院校武术与民族传统体育专业毕业生就业状况的跟踪调查

毕业生的就业状况以及职业发展关乎专业发展方向和趋势。为了推进武术与民族传统体育专业的可持续性发展,采用文献资料法、调查问卷法、数理统计法,调查了2007~2013届北方体育院校武术与民族传统体育专业毕业生的一次就业状况,以及职业发展情况。结果显示,该专业毕业生毕业即就业的比例较低;一次就业地点仍以大中城市为主;进入学校工作的比例最高;并且大多从事非体育专业工作。其中,35.1%武术与民族传统体育专业毕业生曾经发生过工作变动;工作变动后,从事与本专业相关的工作比例仍然较低;在薪金方面,半数以上的的毕业生工资有所提高;而福利待遇、职业规划与工作环境是武术与民族传统体育专业毕业生调动工作的主要原因。由此可见,武术与民族传统体育专业应设立多元化的培养方向,加强学科建设和课程体系改革,为全面提高学生的综合素养奠定学科专业基础。     

Trapping endoplasmic reticulum with amphiphilic AIE-active sensor via specific interaction of ATP-sensitive potassium (KATP)

The current aggregation-induced emission luminogens (AIEgens) sometimes suffer from poor targeting selectivity due to undesirable aggregation in the hydrophilic biosystem with ‘always-on’ fluorescence or unspecific aggregation in the lipophilic organelle with prematurely activated fluorescence. Herein, we report an unprecedented ‘amphiphilic AIEgen’ sensor QM-SO₃-ER based on the AIE building block of quinoline-malononitrile (QM). The introduced hydrophilic sulfonate group can well control the specific solubility in a hydrophilic system with desirable initial ‘fluorescence-off’ state. Moreover, the incorporated p-toluenesulfonamide group plays two roles: enhancing the lipophilic dispersity, and behaving as binding receptor to the adenosine triphosphate (ATP)-sensitive potassium (K_ATP) on the endoplasmic reticulum (ER) membrane to generate the docking assay confinement effect with targetable AIE signal. The amphiphilic AIEgen has for the first time settled down the predicament of unexpected ‘always-on’ fluorescence in the aqueous system and the untargetable aggregation signal in the lipophilic organelle before binding to ER, thus successfully overcoming the bottleneck of AIEgens'' targetability.     

医科院校家庭经济困难学生的心理资本教育探索

当前,对高校家庭经济困难学生的资助已经突破经济资助和精神资助的范畴,逐渐转向能力资助。开发和提升家庭经济困难学生的心理资本,正成为实现能力资助的一个重要渠道。本文通过调研广西几所医科院校,从心理资本的课堂教学和能力资助项目两个方面,阐述了医科院校的心理资本教育现状,并提出在医科院校家庭经济困难学生的心理资本教育中,应实行课堂教学和课外跟踪开发相结合的模式,即跟踪式的心理资本大课堂。     

An Exercise to Introduce Power

In introductory statistics courses, the concept of power is usually presented in the context of testing hypotheses about the population mean. We instead propose an exercise that uses a binomial probability table to introduce the idea of power in the context of testing a population proportion.