Memory for Preselected and Constrained Short Movements

Abstract

The present experiment investigated the recall of terminal location and distance of both preselected and constrained short movements (12 cm ± 4 cm approximately) following 5 second and 30 second unfilled retention intervals. Systematic alteration of the magnitude and direction of the starting position for recall movements revealed that the distance moved markedly interfered with the recall of the terminal location, but distance was essentially recalled independently of terminal location. Recall of distance was superior to terminal location for both the unfilled retention intervals, and there was a decrease in location recall performances following the longer 30 second delay when compared to recall attempts after the shorter 5 second delay. The Findings are discussed in terms of recent proposals to account for the memory for, and control of, discrete limb movements.     

电动计时网络系统的工作流程与相关裁判方法研究

随着电子网络信息技术在田径竞赛尤其是在计时环节中的运用，传统的人工计时及过程的胶片摄影时系统正逐渐退出历史舞台，取而代之的是全新的高智能、数码化的全电动计时网络系统。这个系统的启用更新必然给相关的裁判工作方法带来新的课题。就此对田径运动会电动计时的工作流程及工作内容作简要介绍，并对与此相关的裁判工作方法提出自己的看法。     

城市交通信号灯模拟控制系统设计

城市交通信号灯模拟控制系统模拟了能够对信号灯进行远程投时的城市十字路口控制系统功能。借助于单片机开发板上的已有资源,构建了模拟实际系统功能的单片机扩N82C55控制LED灯模块、8位七段数码管显示控制模块和板上扩展接线模块。在分析实际系统工作流程的基础上,给出了针对单片机开发板的模拟系统C51控制程序流程。用于实际系统时,只需要将代码移植到现场设备并进行具体设置和适当修改即可,可以在满足客户需求的前提下最小化系统开发成本。     

The continuous nature of timing reprogramming in an interceptive task

The time course of movement timing reprogramming was examined in a task requiring temporal coincidence of the conclusion of a forehand drive with the arrival of a moving luminous target at the end of an electronic trackway. The moving target departed from one end of the trackway at a constant velocity of 2?m ^. s^?1, and for a part of the trials its velocity was increased to 3?m ^. s^?1. Target velocity was modified at different moments during stimulus displacement, producing times-to-arrival after velocity increment (TAVIs) from 100 to 600?ms. The effect of specific practice on movement reprogramming was also examined. The results showed early adjustments to the action (TAVIs = 100?–?200?ms) that seemed to be stereotyped, while feedback-based corrections were implemented only at TAVIs of 300?ms or longer. Temporal accuracy was progressively increased as longer TAVIs were provided up to 600?ms. Skill training led to an overall increment of temporal accuracy, but no effect of specific practice was found. The results indicate that timing reprogramming in interceptive actions is a continuous process limited mainly by intrinsic factors: latency to initiate more effective adjustments to the action, and rate-of-movement timing reprogramming.     

择时营养补充方法在优秀自行车运动员营养调控中的应用

目的:为了研究择时营养补充对自行车运动员运动能力的影响和择时营养补充方法在自行车运动员营养调控中的应用,为运动时间营养学理论提供实验依据.方法:对8名优秀自行车运动员在珠海和深圳训练周期内的营养调控进行研究,测试部分血生化指标和心肺功能以及运动现场测试运动能力.结果:本实验发现,运动员在训练期间进行择时营养补充,男子血清总睾水平增加了9.22%(P＜0.05);血清CK水平下降40.61%(P＜0,05);动态追踪Hb、血糖和血胰岛素水平的变化,在训练周期内,Hb呈下降趋势,但仍能维持在较高水平,训练前后比较下降了9.74%(P＜0.05),而血糖浓度和胰岛素水平的波动均在正常范围.结论:以择时营养补充方法应用于优秀自行车运动员训练期间的营养调控,并遵循\"择时补充、联合补充、个体化补充和交替刺激\"的原则,可提高运动员体能和促进体能恢复,对调节内分泌功能、促进运动后骨骼肌机能的快速恢复有积极作用.     

篮球比赛计时计分系统的研发

篮球比赛中用的传统的计时计分系统在先进的电子技术和软件技术的冲击下,亟待改进。文章阐述了新型的篮球比赛计时计分系统的研发思路,运用单片机技术完成系统显示设备的设计工作,利用C＋＋语言开发出了Windows平台下的篮球比赛计时记分系统软件。该系统具有的主要功能有：比赛队员信息录入、队员犯规信息记录统计、队员更换、比分记录、比赛时间记录、24 s倒计时、比赛时间及比分显示等。     

基于破坏性创新的后发企业市场进入时机选择

后发企业选择以何种方式、何种时机进入市场将在很大程度决定着其市场进入的成败以及能否更好地实施后续追赶计划,作为当前创新领域和战略领域研究的前沿和热点,破坏性创新为后发企业的市场进入战略选择提供了一条新路径。本文以破坏性创新理论为基础,借助小米公司在智能手机市场的成功案例对\"后发企业市场进入时机选择\"这一问题进行探索性研究,研究发现:在市场时机选择方面,庞大的市场需求以及层级分明的市场竞争是后发企业能够成功进入市场的前提条件;在技术时机选择方面,成熟的技术、较低的技术获取成本和技术获取难度对于后发企业的市场进入起着重要作用;在产业时机选择方面,新型产业价值链的形成以及成熟的产业环境将在很大程度上决定着后发企业市场进入的成败;在政策时机选择方面,产业政策扶持和融资政策扶持则为后发企业的市场进入提供了更多的保障。     

任务性质、结果反馈时机与运动技能的学习

采用键盘敲击任务探讨任务性质、结果反馈时机对运动技能学习的影响.将100名右优势手大学生随机分为开放性和封闭性任务组(男女各25名),两组分别在5种KR条件下,练习开放或封闭任务3天,每天练习108次.第3天练习结束后休息10min,进行不提供KR的保持测试10次.24 h后,进行无KR保持测试10次.结果显示:(1)在封闭性运动技能学习中延迟KR更有利,而即刻KR促进开放性运动技能的学习;(2)提供KR的适宜时机受任务性质影响.与开放性技能相比,操作封闭性技能时,提供KR的适宜时机应延迟.     

Assimilation Effects in Coincident Timing Responses

Abstract

The purpose of the study was to investigate ways in which gender-related perceptions and actions influenced students' construction of realities in curriculum-in-action in secondary school physical education. The participants were junior and senior secondary school students in a midwestern city in the United States. Data collection methods included observations and interviews. Data were analyzed with inductive analytical procedures. The findings of the study revealed that a majority of the female and male students reproduced traditionally dominant forms of femininity and masculinity. Female students patterned their behavior consistent with feminine ideology in selecting and participating in class activities, and male students chose and participated in class activities along masculine conceptions. The results were interpreted with reproduction and resistance theories. While femininity and masculinity cultures were reproduced through students' choice of activities and participation patterns, these cultures were resisted through students' construction of oppositional behavior.