We assume that when people look around an entire space, the total impression is created through the accumulation of visual information in every direction. We define "brightness of a space" and examine the impact factors and quantification. The results of previous studies suggest that it is reasonable to use average luminance and luminance contrast. However, when the entire space is defined as "brightness of a space", luminance contrast cannot be applied. For this reason, we consider the physical quantity that shows the variation of the brightness in our evaluation experiment on Brightness. It is possible to propose using a prediction equation of " brightness of a space" using the standard deviation of the logarithm of the luminance values and average luminance.
In agriculture, particularly wet rice cultivation, light pollution caused by exterior illumination at night interferes with dark periods and results in delayed flowering (heading). However, we found that by selecting the wavelength of light sources to which rice is exposed and controlling the luminescence, it is possible to bring the time of heading closer to that of a control plot (total darkness). In this study, visibility of artificial illumination using mixed LED (blue, green, yellow-green) was evaluated by comparing it with green LED and white LED illumination. We evaluated five items in this experiment: pedestrian behavior, facial recognition, color recognition, peripheral visual field, and impression. We found that the evaluation for ‘color recognition’ and ‘impression’ were lower for mixed LED than for white LED illumination. Therefore, it is suggested that mixed LED illumination needs to improve in these items.
A light emitting diode (LED) is predicted as a future generation type lighting source which replaces a fluorescent lamp. The effects of LED light on aquatic vegetation using small waterproofed LED equipment (red, blue, and white) as a light supplement combined with a fluorescent lamp were examined. As a result of using this supplement on aquatic vegetation, the growth promoting effects were observed in both red, as well as a mixture of red and a blue LED light. The new LED can be used in the aquarium market by combining a waterproofed LED light source with a fluorescent lamp.