期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
基于频谱分析的光源闪烁评价方法 被引量:1
1
作者 王纪永 牟同升 《光电工程》 CAS CSCD 北大核心 2012年第11期32-36,共5页
针对照明光源普遍存在的闪烁现象,提出了一种基于频谱分析的闪烁评价方法。把时变光信号进行傅里叶变换得到其频域内的功率谱,并通过与人眼视觉对比敏感度相匹配的带通滤波器进行滤波,最后经傅里叶逆变换得到调制后的瞬态光信号波形,据... 针对照明光源普遍存在的闪烁现象,提出了一种基于频谱分析的闪烁评价方法。把时变光信号进行傅里叶变换得到其频域内的功率谱,并通过与人眼视觉对比敏感度相匹配的带通滤波器进行滤波,最后经傅里叶逆变换得到调制后的瞬态光信号波形,据此定义闪烁度来定量表征闪烁程度的大小。对几种典型的光源进行检测并计算其闪烁度,结果与已有实验结论相吻合。该方法结合视觉敏感特性对现有评价方法进行了改进,实现了对光源闪烁的客观度量,给照明优化设计和照明行业标准建立提供了有效借鉴。 展开更多
关键词 频谱分析 傅里叶变换 视觉对比敏感 闪烁度
下载PDF
Contrast Detection Learning Improves Visual Contrast Sensitivity of Cat 被引量:6
2
作者 华田苗 王振华 +1 位作者 徐金旺 刁建刚 《Zoological Research》 CAS CSCD 北大核心 2010年第2期155-162,共8页
Psychological studies on human subjects show that contrast detection learning promote learner's sensitivity to visual stimulus contrast. The underlying neural mechanisms remain unknown. In this study, three cats (Fe... Psychological studies on human subjects show that contrast detection learning promote learner's sensitivity to visual stimulus contrast. The underlying neural mechanisms remain unknown. In this study, three cats (Felis catus) were trained to perform monocularly a contrast detection task by two-altemative forced choice method. The perceptual ability of each cat improved remarkably with learning as indicated by a significantly increased contrast sensitivity to visual stimuli. The learning effect displayed an evident specificity to the eye employed for learning but could partially transfer to the naive eye, prompting the possibility that contrast detection learning might cause neural plasticity before and after the information from both eyes are merged in the visual pathway. Further, the contrast sensitivity improvement was evident basically around the spatial frequency (SF) used for learning, which suggested that contrast detection learning effect showed, to some extent, a SF specificity. This study indicates that cat exhibits a property of contrast detection learning similar to human subjects and can be used as an animal model for subsequent investigations on the neural correlates that mediate learning-induced contrast sensitivity improvement in humans. 展开更多
关键词 VISUAL Contrast detection LEARNING Contrast sensitivity CAT
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部