LED lighting has been widely used in various scenes, but there are few studies on the impact of LED lighting on visual comfort in sustained attention tasks. This paper aims to explore the influence of correlated color temperature (CCT) and illuminance level in LED lighting parameters on human visual comfort. We selected 46 healthy college students (23 male and 23 female). The ages ranged from 22 to 26 years old (average age was 24.2 years). Electroencephalogram (EEG) signals, sustained attention to response test (SART) parameters and subjective evaluation parameters of subjects performing sustained attention tasks under LED lighting were obtained. The results under different conditions were compared, and the effects of experimental lighting parameters on visual comfort were discussed. The results showed that the LED lighting with CCT of 3300 K and illuminance of 300 lx was more comfortable than other combined conditions. In the subjective perception of subjects, 4000 K CCT also had good visual comfort evaluation and caused good task performance. Therefore, our study showed that in sustained attention tasks, when LED lighting conditions were CCT of 3300 and 4300 K and illuminance level was 300 lx, the visual comfort of the subjects was better.

It explores and constructs the principles of waste product redesign which are based on the concept of upcycling. It clarifies the basic concept of upcycling, briefly describes its current development, deeply discusses its value and significance, combines with the idea of upcycling which behinds regeneration design principle from the concept of "4R" of green design, and takes real-life case as example to analyze the principles of waste product redesign. It puts forward five principles of waste product redesign: value enhancement, make the most use of waste, durable and environmental protection, cost control and populace's aesthetic.

This study aimed to explore the differences in the subjects' sustained attention under the impact of nine lighting conditions consisting of the combination of three commonly used correlated color temperature (CCT) (3300 K, 4300 K, and 5300 K) and illuminance levels (300 lx, 500 lx, and 750 lx) to provide guidance on the adjustment of CCT and illuminance level parameters for indoor lighting. We selected 24 physically and mentally healthy university students (12 male and 12 female) as the experimental subjects. The subjects were required to perform sustained attention to response task (SART) activities under the nine different lighting conditions and collected the alpha (α) waves (8–12 Hz) from the electroencephalography signals. Subsequently, the mean power spectral density of the α waves and various SART parameters were analyzed and tested. Finally, the effects of different CCT and illuminance levels on the subjects' attention were compared. With the increase in CCT, the attention level tended to increase linearly, whereas the attention level was the lowest at 300 lx and the highest at 500 lx and appeared as an inverted “U” shape. The subjects' attention level was the highest at the combination of CCT of 5300 K and illuminance level of 500 lx and the lowest at the combination of CCT of 3300 K and illuminance level of 500 lx. These results provide important data to elucidate the impact of lighting condition on attention.

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