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Atthapol Ngaopitakkul - One of the best experts on this subject based on the ideXlab platform.
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The Study of Lighting Quality of LED and HPS Luminaires Based on Various Road Surface Properties
E3S Web of Conferences, 2018Co-Authors: Suntiti Yoomak, Atthapol NgaopitakkulAbstract:This paper presents analysis of lighting quality in different road surface conditions using the DIALux software. Dry and wet road surfaces are used to study lighting quality by following classifications of the International Commission on Illumination (CIE). Lighting quality of high pressure sodium (HPS) and light emitting diode (LED) luminaires are compared, based on roadway with a traffic island. Results indicate that the HPS luminaire can provide better Average ilLuminance and Average Luminance values than the LED luminaire, resulting in positive visual performance. However, the LED luminaire can achieve visual and comfort performance including energy saving due to its light distribution efficiency. For lighting quality on different road surface conditions, the lighter dry road surface materials, the higher lighting quality. Wet road surfaces cause very bright areas on road surface alternating with large dark areas. It results in the Average Luminance of the surface increased while overall uniformity decreased.
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optimisation of lighting quality and energy efficiency of led luminaires in roadway lighting systems on different road surfaces
Sustainable Cities and Society, 2018Co-Authors: Suntiti Yoomak, Atthapol NgaopitakkulAbstract:Abstract Lighting quality plays an important role in determining the visual performance and visual comfort of the road user, which help keep driver alert. Lighting quality depends on various factors, such as mounting height, luminaire spacing, luminaires, overhang, boom angle, and road surface properties. The light that reflects from the road surface enters the eyes of the road user, and makes the road visible. However, prevailing conditions on the roadway determine the reflection properties of the road surface. This paper presents the analysis of lighting quality in different road surface conditions using the DIALux software. Dry and wet road surfaces are used to study lighting quality following the classifications of the International Commission on Illumination (CIE), where the lighting qualities of high-pressure sodium (HPS) and light-emitting diode (LED) luminaires are compared, based on a roadway without a traffic island. In addition, it presents the design of a roadway lighting system with optimised LED luminaires, by adjusting pole spacing and mounting height, ensuring the best installation in each classification of road surface. Thereafter, energy evaluations of different input powers of LED luminaires are discussed and compared with the HPS luminaire. Results indicate that the HPS luminaire can provide better Average ilLuminance and Average Luminance values than LED luminaires, resulting in positive visual performance. However, LED luminaires can achieve better overall visual and comfort performances, including energy saving, due to their light distribution efficiency. For lighting quality in different road surface conditions, the wetter the road surface, the higher the lighting quality; because wet road surfaces cause alternating bright and dark areas on the road. This results in increased Average Luminance of the surface, and decreased longitudinal uniformity. Moreover, road surfaces with high Average Luminance coefficient, Q0, can accommodate larger pole spacing, reducing energy consumption. Using LED luminaires with lower or higher input power than the optimal power, however, result in higher energy consumption.
Seyed Abolfazl Zakerian - One of the best experts on this subject based on the ideXlab platform.
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Safety Evaluation of the Lighting at the Entrance of a Very Long Road Tunnel: A Case Study in Ilam
Safety and health at work, 2016Co-Authors: Ahmad Mehri, Roohalah Hajizadeh, Somayeh Farhang Dehghan, Parvin Nassiri, Sayed Mohammad Jafari, Fereshteh Taheri, Seyed Abolfazl ZakerianAbstract:Abstract Background At the entrance of a tunnel, reflection of sunlight from the surrounding environment and a lack of adequate lighting usually cause some vision problems. The purpose of this study was to perform a safety evaluation of lighting on a very long road in Ilam, Iran. Methods The Average Luminance was measured using a Luminance meter (model S3; Hagner, Solna, Sweden). A camera (model 108, 35-mm single-lens reflex; Yashica, Nagano, Japan) was used to take photographs of the safe stopping distance from the tunnel entrance. Equivalent Luminance was determined according to the Holliday polar diagram. Results Considering the Average Luminance at the tunnel entrance (116.7 cd/m2) and using Adrian's equation, the safe level of lighting at the entrance of the tunnel was determined to be 0.7. Conclusion A comparison between the results of the safe levels of lighting at the entrance of the tunnel and the De Boer scale showed that the phenomenon of black holes is created at the tunnel entrance. This may lead to a misadaptation of the drivers’ eyes to the change in Luminance level at the entrance of the tunnel, thereby increasing the risk of road accidents in this zone.
Suntiti Yoomak - One of the best experts on this subject based on the ideXlab platform.
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The Study of Lighting Quality of LED and HPS Luminaires Based on Various Road Surface Properties
E3S Web of Conferences, 2018Co-Authors: Suntiti Yoomak, Atthapol NgaopitakkulAbstract:This paper presents analysis of lighting quality in different road surface conditions using the DIALux software. Dry and wet road surfaces are used to study lighting quality by following classifications of the International Commission on Illumination (CIE). Lighting quality of high pressure sodium (HPS) and light emitting diode (LED) luminaires are compared, based on roadway with a traffic island. Results indicate that the HPS luminaire can provide better Average ilLuminance and Average Luminance values than the LED luminaire, resulting in positive visual performance. However, the LED luminaire can achieve visual and comfort performance including energy saving due to its light distribution efficiency. For lighting quality on different road surface conditions, the lighter dry road surface materials, the higher lighting quality. Wet road surfaces cause very bright areas on road surface alternating with large dark areas. It results in the Average Luminance of the surface increased while overall uniformity decreased.
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optimisation of lighting quality and energy efficiency of led luminaires in roadway lighting systems on different road surfaces
Sustainable Cities and Society, 2018Co-Authors: Suntiti Yoomak, Atthapol NgaopitakkulAbstract:Abstract Lighting quality plays an important role in determining the visual performance and visual comfort of the road user, which help keep driver alert. Lighting quality depends on various factors, such as mounting height, luminaire spacing, luminaires, overhang, boom angle, and road surface properties. The light that reflects from the road surface enters the eyes of the road user, and makes the road visible. However, prevailing conditions on the roadway determine the reflection properties of the road surface. This paper presents the analysis of lighting quality in different road surface conditions using the DIALux software. Dry and wet road surfaces are used to study lighting quality following the classifications of the International Commission on Illumination (CIE), where the lighting qualities of high-pressure sodium (HPS) and light-emitting diode (LED) luminaires are compared, based on a roadway without a traffic island. In addition, it presents the design of a roadway lighting system with optimised LED luminaires, by adjusting pole spacing and mounting height, ensuring the best installation in each classification of road surface. Thereafter, energy evaluations of different input powers of LED luminaires are discussed and compared with the HPS luminaire. Results indicate that the HPS luminaire can provide better Average ilLuminance and Average Luminance values than LED luminaires, resulting in positive visual performance. However, LED luminaires can achieve better overall visual and comfort performances, including energy saving, due to their light distribution efficiency. For lighting quality in different road surface conditions, the wetter the road surface, the higher the lighting quality; because wet road surfaces cause alternating bright and dark areas on the road. This results in increased Average Luminance of the surface, and decreased longitudinal uniformity. Moreover, road surfaces with high Average Luminance coefficient, Q0, can accommodate larger pole spacing, reducing energy consumption. Using LED luminaires with lower or higher input power than the optimal power, however, result in higher energy consumption.
Jeong Tai Kim - One of the best experts on this subject based on the ideXlab platform.
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A prediction method to identify the glare source in a window with non-uniform Luminance distribution
Energy and Buildings, 2012Co-Authors: Wonwoo Kim, Jeong Tai KimAbstract:Abstract A proper glare prediction method is needed to promote visual comfort. The purpose of this study is to suggest the methodology to identify the glare source, which is necessary in order to control glare coming from windows. Experiments with subjects were conducted in order to evaluate discomfort glare from windows and the features that made the subjects recognize the glare sources in the windows with non-uniform Luminance distributions were explored. Discomfort glare was evaluated in two categories: first across the whole window and then by unit area of the window. The results of the evaluations led to the realization that the discomfort glare value of the whole window is larger than the mean value of the discomfort glares from the window patches. In addition, it is revealed that the evaluated value of discomfort glare is a function of the Average Luminance of the visual field. There is a linear relationship between the Average Luminance of the visual field and the Average Luminance of the glare patches. Such linear relationship has been translated into a formula, whose high accuracy is proven in the study. Using the formula makes it possible to easily identify the window patches that would generate glare.
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The Variation of the Glare Source Luminance According to the Average Luminance of Visual Field
Indoor and Built Environment, 2011Co-Authors: Wonwoo Kim, Jeong Tai KimAbstract:This study was conducted to propose a method of identifying glare sources from windows. Discomfort glare from windows of a classroom was evaluated in the experiments involving subjects, and the features that made the subjects recognize the glare sources in the windows were explored. The results of the evaluation led to the realization that the subjects regarded the patches that were causing discomfort glare as the glare sources on windows. It means that the patches having low Luminance were not the causes of discomfort glare and were excluded from glare sources for the discomfort glare evaluation. There was a linear relationship between the Average Luminance of the visual field and the Average Luminance of the glare patches. The linear relationship has been expressed by a formula. The proposed formula has made it easier to identify the glare patches from windows. The approach as suggested in this study is distinctive to the others by the fact that the glare source was determined based on the Average lumin...
Ahmad Mehri - One of the best experts on this subject based on the ideXlab platform.
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Safety Evaluation of the Lighting at the Entrance of a Very Long Road Tunnel: A Case Study in Ilam
Safety and health at work, 2016Co-Authors: Ahmad Mehri, Roohalah Hajizadeh, Somayeh Farhang Dehghan, Parvin Nassiri, Sayed Mohammad Jafari, Fereshteh Taheri, Seyed Abolfazl ZakerianAbstract:Abstract Background At the entrance of a tunnel, reflection of sunlight from the surrounding environment and a lack of adequate lighting usually cause some vision problems. The purpose of this study was to perform a safety evaluation of lighting on a very long road in Ilam, Iran. Methods The Average Luminance was measured using a Luminance meter (model S3; Hagner, Solna, Sweden). A camera (model 108, 35-mm single-lens reflex; Yashica, Nagano, Japan) was used to take photographs of the safe stopping distance from the tunnel entrance. Equivalent Luminance was determined according to the Holliday polar diagram. Results Considering the Average Luminance at the tunnel entrance (116.7 cd/m2) and using Adrian's equation, the safe level of lighting at the entrance of the tunnel was determined to be 0.7. Conclusion A comparison between the results of the safe levels of lighting at the entrance of the tunnel and the De Boer scale showed that the phenomenon of black holes is created at the tunnel entrance. This may lead to a misadaptation of the drivers’ eyes to the change in Luminance level at the entrance of the tunnel, thereby increasing the risk of road accidents in this zone.
