Browsing by Subject "Outdoor lighting"

Now showing 1 - 3 of 3

Open Access
How to design quality light sources with discrete color components
(Springer, 2019-01) Erdem, Talha; Demir, Hilmi Volkan; Erdem, Talha; Demir, Hilmi Volkan
White light sources using discrete emitters require careful design and optimization. The first step of the design should be determining the intended use of the light source so that application specific requirements can be addressed. Subsequently, optimal designs made of discrete emitters should be determined and finally, experimental implementation of the light source should be carried out. In this Chapter of the brief, we limit ourselves to the use of discrete emitters for indoor and outdoor lighting together with display backlighting applications. For each application, we summarize the requirements that need to be satisfied and present design guidelines to implement quality light sources made of discrete emitters.
Open Access
Lighting monuments: reflections on outdoor lighting and environmental appraisal
(Elsevier, 2006-06) Tural, M.; Yener, C.
For more than 10 years, highlighting urban pattern, revealing the artifacts in our surroundings, and providing relationships among the elements of cities, outdoor lighting practice gained more significance. The following study aims at suggesting the needs for monument lighting, taking it as an essential architectural and outdoor lighting issue, and focuses on aspects to be considered both in the approach and application phases by discussing some examples from Ankara, the capital of Turkey. In order to determine approaches in attaining an effective lighting scheme, a case study was conducted. The participants were shown a series of photographs of the Bilkent University Atatürk Monument and its model taken under daylight and artificial lighting conditions, and the differences and tendencies in their perceptional preferences were examined. The results implied that lighting the monument with down-lighting technique is more preferable compared to up-lighting. The findings also suggested that there is no significant perceptional difference on the figure when daylight condition (direction) is imitated using artificial lighting sources. In the analyses, it was also observed that the difference in the incident angle (45° and 60°) of light did not considerably change the perception of participants. © 2005 Elsevier Ltd. All rights reserved.
Open Access
Photometric design of color-conversion LEDs
(SPIE, 2011) Demir, Hilmi Volkan; Erdem, T.; Nizamoglu, S.; Sun, X. W.
Here the first photometric study of road-lighting white light-emitting diodes (WLEDs) integrated with semiconductor colloidal quantum dots (QDs) is reported enabling higher luminance than conventional light sources, specifically in mesopic vision regimes essential to street lighting. Investigating over 100 million designs uncovers that quality road-lighting QD-WLEDs, with a color quality scale and color rendering index >= 85, enables 13-35% higher mesopic luminance than the sources commonly used in street lighting. Furthermore, these QD-WLEDs were shown to be electrically more efficient than conventional sources with power conversion efficiencies >= 16-29%. Considering this fact, an experimental proof-of-concept QD-WLED was demonstrated, which is the first account of QD based color conversion custom designed for street lighting applications. The obtained white LED achieved the targeted mesopic luminance levels in accordance with the road lighting standards of the USA and the UK. These results indicate that road-lighting QD-WLEDs are strongly promising for energy-saving quality road lighting.