The two currently widely used indexes, Near Point Distance ( NP) and Critical Flicker Fusion Frequency ( CFF), have their intrinsic defects. 目前广泛使用的调节近点距离和闪烁融合频率这二项评价视觉疲劳的指标存在着固有的缺欠。
Under Limited-Band Condition the Precise Solution of Sampling Variance with N-Samples for Frequency Flicker Noise in the Frequency Sources 带限条件下频率闪烁噪声N样本抽样方差的精确解
The calculation of flicker severity can be simplified by discrete algorithm presented in this paper and the analysis results of the error of this algorithm show that in the lower frequency band the error is comparatively small. 离散化算法可简化闪变值的计算过程。文章介绍了闪变值的离散化算法,并对其误差进行了分析,分析结果表明离散化算法在低频段误差较小。
Flicker is introduced because of the asynchronization between the frequency of the lighting system and the captured frame rate which degrades the video quality extremely. 闪烁是由于场景光源与采集设备频率不同步引起的,严重影响视频的质量和压缩效率。
Effect of flight fatigue on critical flicker frequency in airline aircrew of different age groups 飞行疲劳对不同年龄民航飞行人员视觉融合的影响
Results indicate that the direct switching noise induced by flicker noise decreases as LO amplitude increases, and the direct switching noise caused by parasitic capacitor increases with the value of parasitic capacitor and LO frequency. 结果表明,由闪烁噪声引起的直接开关噪声增益随本振幅度递减,由寄生电容引起的间接开关噪声增益随寄生电容值和本振频率递增。
Critical flicker frequency as a potential vision technique in the presence of cataracts 临界闪烁频率作为一项潜在视力检测技术在白内障中的应用
The following parameters were measured: driving performance on the testing ground, visual and auditory reaction time, critical flicker frequency ( CFF), subjective scores of Stanford sleepiness scale ( SSS) and rating of perceived exertion ( RPE). 测定指标包括考核场汽车驾驶能力、视听反应能力和临界闪光融合频率(CFF)、斯坦福嗜睡量表和自认疲劳分级量表评分。
This method can accurately find out the start time of flicker signals and use FFT to detect the frequency and amplitude of the flicker signals in the following. 该算法可以准确定位闪变分量出现的位置,并从该时刻起进行快速傅立叶变换(FFT),从而得到包络信号的频率及幅值。
The author illuminates the generating process and technique of some power quality problems, such as voltage sag, unbalance, voltage fluctuation, flicker, harmonic as well as frequency deviation. 说明了电压凹陷、三相不平衡、电压波动与闪变、谐波及频率变动的发生过程,并在这些基础上给出了所实现装置的参数与特征。
This paper addresses the buildup of an electric power supply and distribution system as well as equipment configuration of a frequency variable speed regulation system in Ku-Shan Oil Pipeline and describes the phenomena of voltage offset, voltage flicker, voltage distortion and frequency offset. 介绍了库鄯输油管道供配电系统的组成及变频调速系统的设备配置,对电网波动造成的电压偏移、电压闪变、电压畸变、频率偏移等现象进行了阐述。
Judgment accuracy, Critical Flicker Frequency ( CFF), and subjective evaluation were compared between these two groups after the tasks. 实验结束后,对比两组实验测试指标的变化,这些指标主要包括判断正确率、闪频以及主观评价。
Second, the noise of double balanced mixer was analyzed, which involved analysis of low frequency flicker noise and high frequency thermal noise. 接着对双平衡混频器的噪声进行理论分析,包括低频闪烁噪声和高频热噪声。
This method not only can achieve the distortionless envelope detection of voltage flicker, but also can detect the time, frequency and amplitude of the signal accurately. 该方法不仅能够对电压闪变信号进行不失真地包络检波,而且能够精确地检测电压闪变信号的时间和包络信号的频率分量及其幅度。
The heart rate increased and the critical flicker fusion frequency decreased during walking, but no significant differences were observed between different walking times. 结果表明,劳动后心率升高,闪光融合频率降低,但不同劳动时间之间无明显差别。
Using DWT instead of traditional low-pass filter, which not only can achieve the real synchronous wave detection of voltage flicker, but also can detect the time, frequency and amplitude of the signal. 用小波子带滤波器代替传统的低通滤波器,不仅能够对电压闪变信号进行不失真的包络检测,且能够检测出电压闪变信号发生的时间、频率以及幅值。
By using the relation between the Allan variance and the power spectrum law's mode of noise we can distinguish phase, white frequency, flicker frequency and frequency randon walk noises, but can not distinguish white phase noise from fricker phase noise. 应用时域阿仑(Allan)方差与幂律谱噪声模型的关系,可以区分调相噪声,调频白噪声,调频闪交噪声和频率随机游动噪声。但不能区别调相白噪声和调相闪变噪声。
Effect of critical flicker frequency training on enhancing the visual acuity 闪光临界融合频率训练对提高视敏度的影响
Selective reaction time was decreased and flicker fusion frequency was increased, which provide substantial evidence of a change in cognitive performance after saturation exercise. 小深度的饱和潜水训练后,潜水员的选择反应时缩短,闪光融合频率增大,提示潜水训练对部分认知能力有影响。
The fundamental frequency of flicker is twice as high as power frequency. The flicker index by induction ballast is more than 10%, and it is increasing sharply as reducing power voltage or illuminance. 闪烁基频为工频频率的二倍,采用电感镇流时闪烁高达10%以上,降压或调光则急剧增加。
AIM: To determine the temporal acuity with JGW-B1 psychological experimental desk flicker apparatus, and improve the horary visual acuity of subjects with critical flicker frequency ( CFF) training method. 目的:观察采用JGW-B1型心理实验台光点闪烁仪部分测定时间视敏度,并以闪光临界融合频率的训练方法对健康志愿者空间和时间视敏度的影响。
At the same time, with the rapid development of electric power industry, stabile power quality issues, such as voltage fluctuation and flicker, frequency fluctuation, harmonics, have increasingly captured considerable attention from utility companies and their customers. 同时,随着电力工业的快速发展,稳态电能质量问题如电压波动、频率波动、谐波等,已经引起了足够的重视。
In features extraction step, system extracts four eigenvalues like high/ low frequency energy, color saturation energy and average boundary flicker frequency. The eigenvalues were based on the semitransparent and flickering characters of smoke. 在特征提取环节中,根据烟雾的半透明性和闪烁频率两种特性系统提取了可疑图元的高低频能量,颜色饱和度能量和边界平均闪烁频率四种特征值。
Through the comprehensive analysis of the static and dynamic characteristics of the fire flame, this issue mainly study the features of fire flame include color of the flame of fire, the scale of round, the number of cusp, flicker frequency and changes in area. 本课题通过对火灾火焰的静态和动态特征综合分析后,将火灾火焰的颜色、尖角数、圆形度、闪烁频率以及面积变化等特征作为主要研究内容。
The flame has complex change process and forms in the burning process. Its color features, flicker frequency characteristic, relative stability characteristic, space change information and irregular shape characteristic are extracted by observing. 火焰在燃烧过程中具有复杂的变化过程和表现形式,通过观察,本文提取出火焰的颜色特征、闪动频率特征、相对稳定性特征、空间信息丰富及形状不规则特征。