城市交通信号灯模拟控制系统设计     

潘晓东  潘晓宁 《深圳信息职业技术学院学报》2009,7(2):39-44

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。  相似文献   

Independence of reaction time and response force control during isometric leg extension     

Tatsuyuki Ohtsuki ‡ 《Journal of sports sciences》2013,31(4):373-382

In this study, we examined the relative control of reaction time and force in responses of the lower limb. Fourteen female participants (age 21.2±1.0 years, height 1.62±0.05?m, body mass 54.1±6.1?kg; mean±s) were instructed to exert their maximal isometric one-leg extension force as quickly as possible in response to an auditory stimulus presented after one of 13 foreperiod durations, ranging from 0.5 to 10.0?s. In the ‘irregular condition’ each foreperiod was presented in random order, while in the ‘regular condition’ each foreperiod was repeated consecutively. A significant interactive effect of foreperiod duration and regularity on reaction time was observed (P?<?0.001 in two-way ANOVA with repeated measures). In the irregular condition the shorter foreperiod induced a longer reaction time, while in the regular condition the shorter foreperiod induced a shorter reaction time. Peak amplitude of isometric force was affected only by the regularity of foreperiod and there was a significant variation of changes in peak force across participants; nine participants were shown to significantly increase peak force for the regular condition (P?<?0.001), three to decrease it (P?<?0.05) and two showed no difference. These results indicate the independence of reaction time and response force control in the lower limb motor system. Variation of changes in peak force across participants may be due to the different attention to the bipolar nature of the task requirements such as maximal force and maximal speed.  相似文献   

The continuous nature of timing reprogramming in an interceptive task     

Luis Augusto Teixeira  Elke Dos Santos Lima  Mariana Marília Franzoni 《Journal of sports sciences》2013,31(9):943-950

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.  相似文献   

Memory for Preselected and Constrained Short Movements     

Warren D. Walsh 《Research quarterly for exercise and sport》2013,84(3):368-379

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.  相似文献   

Assimilation Effects in Coincident Timing Responses     

Douglas L. Weeks  Charles H. Shea 《Research quarterly for exercise and sport》2013,84(1):89-92

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.  相似文献   

Two-Handed Movement Control     

Daniel M. Corcos 《Research quarterly for exercise and sport》2013,84(2):117-122

Abstract

The purpose of this study was to investigate the discrepancy between the finding that when two hands make movements to targets of different distances, they have the same movement time (Kelso, Southard & Goodman, 1979a, b) and the finding that they have different movement times (Marteniuk & MacKenzie, 1980). The present experiment shows that when the ratio of the distance traveled by the two hands is 4:1, they do not take the same time. The hand moving the shorter distance lakes less time, although it takes more lime than when moving alone or when moving the same distance as the other hand. This finding is highlighted when individual data are examined. It appears that there is no difference between using homologous or nonhomologous muscle groups.  相似文献   

The Effects of Visual and Auditory Models on the Learning of a Rhythmical Synchronization Dance Skill     

Irina J. Wuyts  Martinus J. Buekers 《Research quarterly for exercise and sport》2013,84(2):105-115

The purpose of this study was to investigate the effect of visual and auditory concurrent models on the acquisition of a rhythmical synchronization task. Subjects attempted to synchronize a series of dance steps to the beat of two auditory rhythms. Subjects performed five trial blocks in one of four practice conditions: (a) audio-visual (auditory rhythms combined with a visual model), (b) audio-auditory (auditory rhythms combined with an auditory model), (c) auditory only (auditory rhythms with no model), and (d) visual only (no auditory rhythms but exposure to a visual model). Rhythmical timing and synchronization accuracy served as the dependent variables. Results revealed no practice condition learning differences for rhythmical timing. For synchronization accuracy, the audio-auditory group produced significantly lower error scores at acquisition, but no differences were found at retention. Apparently, the availability of models created an information dependency that resulted in a decrease of performance and, consequently, no group differences in retention.  相似文献   

Response Timing Accuracy of Long-Distance Movements     

Jan M. Jasiewicz  Roger W. Simmons 《Research quarterly for exercise and sport》2013,84(3):371-374

Abstract

The purpose of the study was to compare the effectiveness of the Red Cross and Silvia methods of teaching beginning swimming. College women (N = 76), who were beginners in swimming, served as subjects. Pretests indicated no differences among the four classes prior to instruction. Reliability coefficients of the post-tests for distance and survival time (test-retest method) ranged from .70 to .98. ANOVA procedures utilizing front crawl distance, back crawl distance, survival time, and length of time required to pass the Red Cross combined tests as dependent variables resulted in superiority of the Silvia method over the Red Cross method in each analysis.  相似文献   

增益开关激光脉冲时基抖动的测量方法     

李怀繁  杨成全  李海 《雁北师范学院学报》2006,22(5):38-40

分析了增益开关激光脉冲抖动产生的原因及其分类.系统介绍了取样示波器法、相位噪声法、谐波分析法和互相关法等测量脉冲抖动的方法,并总结了它们的优缺点及适用范围.  相似文献   

The effects of explicit timing on middle‐school students’ writing production across 5‐ and 15‐min sessions     

Peter L. Ignacio  Merilee McCurdy  Jada White  Madeline B. Auge  Christopher H. Skinner  Janet Schwartz‐Micheaux 《Psychology in the schools》2019,56(9):1482-1492

Enhancing rates of accurate, active, academic responding can enhance learning. Both temporal manipulations (i.e., reducing time to work on assignments) and providing multiple distributed temporal cues (MDTC), sometimes referred to as explicit timing, have been shown to enhance rates of accurate mathematics responding. The current study was designed to evaluate the effects of session length (i.e., 5 vs. 15 min to write) and temporal cues (i.e., a single initial temporal cue vs. MDTC) on seventh‐ and eighth‐grade students writing assignment rates and writing accuracy. Results showed that the 5 min writing sessions did result in significantly greater rates of accurate responding than the 15 min sessions; however, explicit timing did not significantly alter writing rates or accuracy. These findings suggest that educators can enhance rates of accurate writing by reducing writing session lengths. Discussion focuses on applied implications of providing briefer writing sessions and future research investigating the interaction between multiple temporal cues and assignments.  相似文献