坑道操对坑道作业人员反应时昼夜节律及调整的研究

以现代时间生物学理论为指导,应用单个余弦法进行生物节律分析和数据统计,观察在坑道环境中,正常作息制和光暗倒相制下坑道作业人员反应时的昼夜节律相位情况,以及坑道操对反应时节律的相位影响特点及规律。结果表明在正常作息制条件下,反应时表现明显的昼夜节律（P〈0.05）。在光暗倒相状态下,坑道操组表现明显的昼夜节律（P〈0.05）,而对照组不具有明显的昼夜节律。坑道操对反应时具有明显的调节作用。     

谈对企业固定资产管理必须把握资金时间价值理念

固定资产在企业生产经营活动中处于重要地位,具有价值大、耗资多、使用年限长、投资风险大等特点,有效提高固定资产使用效率,可以为企业带来更多收益。资金时间价值是货币随着时间的推移而发生的增值,是客观存在的经济范畴,它的运用对于固定资产管理起到决定性的作用。所以对企业固定资产管理无论在会计实务中还是从财务管理角度都要把握资金时间价值理念。     

让美剧来敲门——论英语听力问题和美剧的作用

英语听力是英语学习中难以攻克的部分,而中国学生普遍在英语听力中存在各种问题.美剧正是练习听力绝佳的途径.美剧在提高学生听力中的作用不可忽视,选择合适的美剧及掌握恰当的方式可以帮助学生克服听力的盲点,提高听力水平,并享受听英语的乐趣.     

室内风机延时对空调衰减系数Cd影响的研究

介绍Cd的计算方法,试验研究了室内风机延时时间对Cd系数的影响。测试数据表明,为实现最低的Cd系数,室内风机的延时时间存在一个最佳数值;测试的机组,其最佳延时时间为120秒。风机延时可以提高整机SEER大约0．2,即1．3％。     

基于多注意力的多变量时间序列特征选择方法

特征选择是避免维度诅咒的一种数据预处理技术。在多变量时间序列预测中,为了同时找到与问题相关性最大的变量及其对应时延,提出一种基于多注意力的有监督特征选择方法。该方法利用带有注意力模块和学习模块的深度学习模型,将原始二维时间序列数据正交分割成两组一维数据,分别输入两个不同维度的注意力生成模块,得到特征维度和时间维度的注意权重。两个维度的注意力权值点积叠加作为全局注意力得分进行特征选择,作用于原始数据后输入随学习模块训练不断更新至收敛。实验结果表明,所提出的方法在特征数小于10时可达到全量数据训练效果,与现有几种基线方法相比实现了最佳准确率。     

交通信号灯迭代学习控制方法

由于城市交通信号灯控制存在着非线性动态特性,对其进行控制时很难进行精确的数学建模,同时路口交通流具有重复性特点,呈现明显的周期性特征。为了减少路口车辆等待时间、提高通行效率,利用迭代学习控制方法,对信号灯周期和各个相位有效绿灯时间进行优化,从而对路口绿灯进行最大化利用,保证车辆在路网中能够高效、平稳地通行。仿真结果表明,在迭代次数达到 15 次之后,排队长度相位差和误差都趋于零,减少了交通拥堵时间。     

时标上具有界和无界时滞的Cohen—Grossberg神经网络的全局指数稳定性

本文在时标上研究了具有有界和分布时滞的Cohen-Grossberg神经网络,应用压缩映射原理、Lyapunov泛函方法和一些分析技巧,得到该模型平衡点的存在性和全局稳定性的充分条件.本文是首次应用时标理论将相同框架下的Cohen-Grossberg神经网络的连续系统和离散系统统一起来.     

中国特色社会主义理论体系与中国传统文化

中国特色社会主义理论体系与中国传统文化相互联系、不可分割。一方面,中华民族优秀的传统文化是中国特色社会主义理论体系重要的思想来源,汲取中华民族传统文化之精华,中国特色社会主义理论体系得以进一步丰富和发展。另一方面,中国特色社会主义理论体系又对中国传统文化进行了马克思主义的改造,使之更具鲜活生机。     

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

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.     

Time motion analysis of 2001 and 2002 super 12 rugby

The aim of this study was to quantify movements of Super 12 rugby players in competition because information on elite rugby players' movements is unavailable. Players were categorized into forwards [front (n = 16) and back row (n = 15)] and backs [inside (n = 9) and outside backs (n = 7)] and their movements analysed by video-based time motion analysis. Movements were classified as rest (standing, walking and jogging) and work (striding, sprinting, static exertion, jumping, lifting or tackling). The total time, number and duration of individual activities were assessed, with differences between groups evaluated using independent sample t-tests (unequal variances), while differences between halves were assessed with paired sample t-tests. Forwards had 7:47?min:s (95% confidence limits: 6:39 to 8:55?min:s, P<0.01) more time in static exertion than backs, but backs spent 0:52 (0:34 to 1:09, P = 0.01) min:s more time sprinting than forwards, and had a 0.7 (0.3 to 1.2, P = 0.01) s longer duration of each sprint. Forwards spent 7:31 (5:55 to 9:08) min:s more time in work activities (P = 0.01) and had 2.1 (1.3 to 2.8) s longer work durations (P<0.01) than backs. The results indicate frequent short duration (<4?s) work efforts followed by moderate duration (<20?s) rest for forwards, and extended (>100?s) rest duration for backs. High-intensity efforts involved static exertion for forwards (mean?±?standard deviation frequency = 80?±?17) and sprinting for backs (27?±?9). In conclusion, after nearly a decade since becoming professional, elite rugby union is still characterized by highly intense, intermittent movement patterns and marked differences in the competition demands of forwards and backs.