Color Temperature and Wavelength Control of LED Lighting based on CIE1931 xy Chromaticity Diagram

2017 ◽  
Vol 54 (11) ◽  
pp. 175-181
Author(s):  
Juyeon Lee ◽  
Daesoon Kim ◽  
Woonchul Ham
Keyword(s):  
Color Temperature ◽  
Chromaticity Diagram ◽  
Led Lighting ◽  
Wavelength Control

Implementation of smartphone-based color temperature and wavelength control LED lighting system

2016 ◽  
Vol 19 (2) ◽  
pp. 949-966 ◽  
Author(s):  
Seung-Mi Moon ◽  
Sook-Youn Kwon ◽  
Jae-Hyun Lim
Keyword(s):  
Color Temperature ◽  
Lighting System ◽  
Led Lighting ◽  
Wavelength Control

scholarly journals Effect of LED Lighting Illuminance and Correlated Color Temperature on Working Memory

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Chung Won Lee ◽  
Jin Ho Kim
Keyword(s):  
Working Memory ◽  
Standard Deviation ◽  
Repeated Measures ◽  
Memory Performance ◽  
Light Condition ◽  
Bright Light ◽  
Color Temperature ◽  
Led Lighting ◽  
Temperature Conditions ◽  
Lighting Conditions

This study was conducted to verify how the illuminance and correlated color temperature of LED lighting affect working memory. For this study, an automatic LED lighting device based on a light sensor was developed and used, and the lighting conditions were treated with a total of six conditions (2 × 3): two illuminance conditions (dim: 400 lx, bright: 1,000 lx) and three correlated color temperature conditions (3,000 K, 5,000 K, and 7,000 K). There were 30 participants in the study, and the average age was 21.6 years (Standard deviation = 1.92). Participants were assigned to all six lighting conditions, and the placement order was randomized. For the measurement of working memory, 3-back task was used and the correct responses for 5 minutes were used as a dependent variable. As a result of repeated measures analysis of variance (ANOVA), both illuminance and correlated color temperature were found to be significant variables affecting working memory, and no interaction effect between illuminance and correlated color temperature was found. As a result of the post hoc verification conducted thereafter, the working memory performance in the bright light condition (1,000 lx) was 48.32 (Standard deviation = 15.63) on average, compared to 44.80 (Standard deviation = 15.29) in the relatively dim condition (400 lx). It was found that the condition of bright light was superior in performing working memory compared to relatively dim condition. The working memory performance in the correlated color temperature condition (5,000 K) was 48.32 (Standard deviation = 16.41) on average and higher than that of other color temperature conditions. As a result, working memory performance was the best in 1,000 lx, 5,000 K condition Mean = 53.43 (Standard deviation = 18.38), and 400 lx, 7,000 K condition Mean = 42.73 (Standard deviation = 17.68) showed the worst performance of working memory.

scholarly journals The Influence of LED Lighting in School Recreation Areas on Visual Acuity and Psycho-Emotional State of First Graders in the Dynamics of a Schoolyear

2019 ◽  
pp. 25-30
Author(s):  
NA Skoblina ◽  
OYu Milushkina ◽  
AM Kurgansky ◽  
SV Markelova ◽  
AP Tsameryan ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Emotional State ◽  
First Graders ◽  
Color Temperature ◽  
Light Sources ◽  
Color Test ◽  
Led Lighting ◽  
Light Load ◽  
Recreation Areas ◽  
The Impact

Object: The wide spread of gadgets among modern schoolchildren and their intensive use during breaks in school corridors and recreation areas indicates the necessity of improving illumination in school recreation areas to secure conditions suitable for intensive visual work. Thanks to their technical characteristics, durability and affordable price, LED light sources can ensure the implementation of this task. The objective of the study was to assess the impact of LED lighting of school corridors, halls and recreational facilities on visual acuity and psycho-emotional state of first graders in the course of a schoolyear. Materials and methods: In the corridors and recreation areas of the Dolgoprudninskaya Gymnasium (Moscow Region), fluorescent lamps were replaced by PrLUX-AU-36 LED lamps with Epistar LEDs, opal diffuser, 3600Lm luminous flux, and the color temperature of 4000K. Measurements of artificial lighting were taken before and after installing LED lamps using a TKA PKM 43 light meter. We conducted a study of visual acuity among 67 first graders (aged 7-8) in the annual dynamics from September to May using the Sivtsev-Golovin table placed in the Rota apparatus. Testing was conducted by a highly qualified ophthalmologist. The psycho-emotional state was assessed using the Luscher color test. Results: We observed a significant increase in visual acuity in children over the specified period indicating the absence of negative effects of LED lighting on the organ of vision. The results of the Lusher test proved the absence of negative dynamics, thus demonstrating null adverse health effects of LED lighting in the primary schoolchildren. The studies confirmed that the influence of that light load on vision and its negative non-visual effects were only potential.

scholarly journals Development and Implementation of a Self-Optimizable Smart Lighting System Based on Learning Context in Classroom

2020 ◽  
Vol 17 (4) ◽  
pp. 1217
Author(s):  
Baoshi Sun ◽  
Qiaoli Zhang ◽  
Shi Cao
Keyword(s):  
Student Performance ◽  
Light Emitting Diode ◽  
Environmental Parameters ◽  
Environmental Data ◽  
Color Temperature ◽  
Lighting System ◽  
Learning Context ◽  
Led Lighting ◽  
Smart Lighting ◽  
Lighting Systems

Illumination is one of the most important environmental factors in the classroom. Researchers have discovered that lighting settings have significant impact on students’ performance. Although light-emitting diode (LED) lighting systems can precisely control brightness level and correlated color temperature (CCT), existing designs of LED lighting control systems for classrooms are focused on energy-saving but lack context-based illumination control ability. In this study, a smart lighting system with continuous evolution capability was developed. It can adjust brightness, CCT, and illuminance distribution dynamically according to specific learning context. This system allows not only manual control, but also automatic switching of scenes by integrating with school schedules. Based on existing knowledge about lighting preference, 10 lighting modes confined in the comfortable zone of Kruithof curve were proposed for various classroom scenarios. Moreover, a classroom environmental data-processing framework for collecting and analyzing learning context, illumination settings, environmental data, and students’ performance data was introduced. This framework can help researchers explore the correlation between student performance and environmental parameters.

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