基于时间约束的序列模式挖掘算法研究     

Shan Siqing Li Xiaona 《石家庄铁路工程职业技术学院学报》2007,(3)

传统关联规则挖掘算法所讨论的只是一次事务内部的模式,但实际应用中随着时间的推移,事务之间会有某种联系或发展趋势,传统关联规则算法则无法揭示其中的规律。将在SPAM算法的基础上进行改进,加入通用时间约束,提出一个新算法——TSPAM算法。TSPAM算法采纳SPAM算法中的相关概念和方法,在SPAM算法的裁减部分和候选集的生成部分进行改进,对其加入时间约束。实验表明新算法对挖掘具有时间特征的序列模式是行之有效的。  相似文献   

自动与控制计时系统脑机制研究     

陈有国  彭春花  张志杰  黄希庭 《西南师范大学学报(人文社会科学版)》2008,34(4):9-14

脑成像与神经心理学的研究均提供了存在自动计时系统与控制计时系统的证据。对时间信息自动加工的研究表明,自动计时系统与运动系统关系密切,均包含小脑、基底神经节和辅助运动区。对时间信息控制加工的研究表明,包括背外侧前额叶皮质的额叶一纹状体回路为认知控制计时系统与工作记忆的基础,时间信息加工的注意调节系统较复杂,涉及区域主要包括前辅助运动区、右岛盖、顶叶、前扣带皮质。自动加工与控制加工并不是截然分离的,两个系统激活区域和激活强度存在差异,两个系统时间范围不存在清晰的分界点。  相似文献   

论话本小说创作的浙江特征及其时空构建的浙江属性   总被引：1，自引：0，他引：1  

李桂奎 《湖州师范学院学报》2003,25(5):10-15

南宋以后，浙江政治、经济、文化的全面发展给话本小说创作的繁荣带来了契机，其地理优势、文化传统以及先进的印刷技术。不仅培育了一大批土生土长的话本小说大家，而且还生发出许多令人喜闻乐道的故事。一方面，浙江的节日风俗为话本小说提供了带有地方人文色彩的叙事时间刻度；另一方面，作为事故的多发地带和情缘的多现场所，浙江的水域为话本小说提供了广阔的叙事空间。可以说，话本小说的创作带有鲜明的浙江地域特征。而其时空构建也显示出浓厚的浙江属性。  相似文献   

第四十九届世界乒乓球团体锦标赛暂停时机研究   总被引：1，自引：0，他引：1  

王道平  许玲 《体育科技文献通报》2009,17(7):28-29,31

通过研究第四十九届世界乒乓球团体锦标赛的暂停，分析他们的暂停时机，结果显示：暂停时机是以尾盘局为主导的战略思想，但非尾盘局也是不可忽视领域；一场比赛中第三局的暂停最活跃；一局的暂停时机偏向于较高比分的中、尾局；双方9平以后、领先后被追2分、差距被拉开3分时的暂停为最佳的时机。  相似文献   

时间规则的修改对篮球运动的影响   总被引：2，自引：0，他引：2  

邱红武  陈志贤 《体育科学研究》2006,10(2):19-21

从现代篮球运动发展来看,篮球规则中的时间规则经过多次增减和修改,促进了篮球技术、战术的发展,大大地提高了攻守转换速度,以适应现代篮球运动发展的客观需求。  相似文献   

基于Proteus的555级联电路的仿真及频率计算     

田清华 《石家庄职业技术学院学报》2012,24(6):26-30

分析了救护车报警电路和555定时器的工作原理,用Proteus组合555芯片、电阻、电容对救护车报警电路进行了仿真,并将其仿真波形在同一屏幕上呈现出来,计算了其频率,计算结果与仿真结果一致.  相似文献   

Reaction Time and Anticipation Time: Effects of Development     

Jerry R. Thomas  Jere D. Gallagher  Gracie J. Purvis 《Research quarterly for exercise and sport》2013,84(3):359-367

Abstract

The developmental nature of reaction time (RT) and anticipation timing (AT) performance, as well as the relationship between them, was investigated using 15 male and 15 female subjects at each of five age levels—7, 9, 11, 13, and 20 yrs. Each subject was given 40 trials for both RT and AT performance with task order counterbalanced. Results indicated that as age increased RT decreased, with males having more rapid RT than females. The two younger age groups differed from the three older groups on AT performance. RT was significantly correlated with AT (|CE| measure) for the 7, 9, and 11 yr old males but not in any other age by gender condition. Apparently neither young males nor young females have a good motor plan in memory to control AT performance. However, the more rapid RT (and thus better response initiation) of the males allows better AT performance at the younger ages. Beginning about 10–11 yrs of age, better motor plans are developed in children's memory system, leading to less reliance on rapid RT for good AT performance, and thus the correlation between RT and AT performance is not present.  相似文献   

Responses to Speed Changes in Coincidence-Anticipation Judgments after Extended Practice     

Kathleen M. Haywood 《Research quarterly for exercise and sport》2013,84(1):28-32

Abstract

Coincidence-anticipation performance has been found to vary with changes in the speed of the task's stimulus. This may be due to bias effects. The present study was designed to investigate the existence of directional error, its persistence after extended practice, and its occurrence upon transfer to new contextual stimuli. Two groups of 20 women athletes each were tested for 270 trials over 3 days on a Bassin anticipation task. One group judged stimulus speeds of 2, 3, and 4 mph and the other group speeds of 2, 4, and 6 mph. Both groups improved during training, but tended to respond late, less accurately, and more variably to the slowest speed. Following a 30-trial warmup on Day 4, the second group transferred to the same speeds given the first group. Following transfer, the Transfer Group demonstrated increased directional bias to the slowest stimulus speed despite having seen this speed throughout training. By the second block of trials following transfer, however, they were performing at an error level similar to that of the Control Group. The present findings are in agreement with those concerning psychophysical judgments, and suggest that skill acquisition may be subject to bias effects if the task involves judgments of varying speeds.  相似文献   

Effects of Series Elasticity on the Human Knee Extension Torque-Angle Relationship in Vivo     

Suzete Chiviacowsky  Gabriele Wulf 《Research quarterly for exercise and sport》2013,84(4):408-415

Abstract

This paper examines whether self-controlled feedback schedules enhance learning, because they are more tailored to the performers' needs than externally controlled feedback schedules. Participants practiced a sequential timing task. One group of learners (self-control) was provided with feedback whenever they requested it, whereas another group (yoked) had no influence on the feedback schedule. The self-control group showed learning benefits on a delayed transfer test. Questionnaire results revealed that self-control learners asked for feedback primarily after good trials andyoked learners preferred to receive feedback after good trials. Analyses demonstrated that errors were lower on feedback than no-feedback trials for the self-control group but not for the yoked group. Thus, self-control participants appeared to use a strategy for requesting feedback. This might explain learning advantages of self-controlled practice.  相似文献   

基于USB2.0和FPGA的高速数据采集卡     

王鹏  吴尘 《南通职业大学学报》2010,24(3):91-94

介绍一种采用USB2.0接口与PC机进行数据传输的高速数据采集卡的设计。采集卡由可变增益放大器对采样信号进行预处理,使用异步并行的A/D转换技术实现40 Msps的数据采集,由FPGA实现时序控制和数据高速FIFO,由内嵌MCU的USB控制器实现USB2.0接口功能。文章给出了硬件的基本结构和软件固件设计的基本方法,并对用FPGA设计FIFO作了重点阐述,同时对使用异步并行A/D转换与使用采样率为40 Msps的ADC器件的采样数据在FIFO内的数据传输进行了时序仿真,分析了仿真结果。  相似文献