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Author Xavier Kerola, D.
Title Modelling artificial night-sky brightness with a polarized multiple scattering radiative transfer computer code: Modelling artificial night-sky brightness Type Journal Article
Year 2006 Publication Monthly Notices of the Royal Astronomical Society Abbreviated Journal
Volume 365 Issue 4 Pages 1295-1299
Keywords Skyglow; modeling; radiative transfer; Gauss-Seidel; light pollution; Garstang model
Abstract As part of an ongoing investigation of radiative effects produced by hazy atmospheres, computational procedures have been developed for use in determining the brightening of the night sky as a result of urban illumination. The downwardly and upwardly directed radiances of multiply scattered light from an offending metropolitan source are computed by a straightforward Gauss-Seidel (G-S) iterative technique applied directly to the integrated form of Chandrasekhar's vectorized radiative transfer equation. Initial benchmark night-sky brightness tests of the present G-S model using fully consistent optical emission and extinction input parameters yield very encouraging results when compared with the double scattering treatment of Garstang, the only full-fledged previously available model.
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0035-8711 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 278
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Author Johansson, M.; Pedersen, E.; Maleetipwan-Mattsson, P.; Kuhn, L.; Laike, T.
Title Perceived outdoor lighting quality (POLQ): A lighting assessment tool Type Journal Article
Year 2013 Publication Journal of Environmental Psychology Abbreviated Journal Journal of Environmental Psychology
Volume 39 Issue Pages 14-21
Keywords Perception; Street lighting; Observation-based environmental assessment; Urban space
Abstract A shift towards more energy-efficient light sources for outdoor lighting such as light-emitting diodes (LEDs) is underway. Photometric measures are not sufficient to capture how users experience the light, so complementary tools are required. This study aimed to develop an observer-based environmental assessment tool, based on bipolar semantic differentials, for outdoor lighting in urban spaces. Exploratory (N = 130) and confirmatory (N = 117) factor analyses of observations of lighting installations made by laypersons on-site along pedestrian paths, resulted in two dimensions of high reliability: the Perceived Strength Quality (PSQ, Cronbach's alpha = 0.82–0.85) and the Perceived Comfort Quality (PCQ, Cronbach's alpha = 0.77–0.81). PSQ and PCQ differentiated between light sources of different illuminance level, colour temperature and colour rendering. Regression analyses showed that the perceived lighting qualities helped to explain the variance in visual accessibility, whereas PCQ helped to explain perceived danger in the environment. The perceived lighting qualities can add to the understanding of pedestrians' perception of outdoor lighting, and is proposed as a complementary tool for development of sustainable light designs in the urban environment.
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Language (up) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0272-4944 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 279
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Author Kuhn, L.; Johansson, M.; Laike, T.; Goven, T.
Title Residents' perceptions following retrofitting of residential area outdoor lighting with LEDs Type Journal Article
Year 2013 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technology
Volume 45 Issue 5 Pages 568-584
Keywords *Lighting; outdoor lighting; LED; light emitting diode; lighting levels; public opinion
Abstract The use of light emitting diodes (LEDs) in outdoor lighting has energy-saving potential, but users’ responses to this light source are largely unknown. An intervention study in two residential areas compared conventional lighting installations (high pressure sodium in Area 1 and high pressure mercury in Area 2) to a retrofitted LED-alternative regarding residents’ perceptions of quality of light, visual accessibility and danger. Moreover, energy use was calculated. Residents’ (N = 60) visual accessibility improved and perceived danger remained low in both areas after retrofitting. In Area 2 the perceived quality of light increased, whereas in Area 1 the results were mixed. The retrofitted application reduced energy use by 41–76% and might be a feasible alternative to conventional outdoor lighting in relatively safe areas.
Address Environmental Psychology, Department of Architecture and Built Environment, Lund University, Lund, Sweden
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Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1477-1535 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 280
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Author Zukauskas, A.; Vaicekauskas, R.; Tuzikas, A.; Petrulis, A.; Stanikunas, R.; Svegzda, A.; Eidikas, P.; Vitta, P.
Title Firelight LED Source: Toward a Balanced Approach to the Performance of Solid-State Lighting for Outdoor Environments Type Journal Article
Year 2014 Publication IEEE Photonics Journal Abbreviated Journal IEEE Photonics J.
Volume 6 Issue 3 Pages 1-16
Keywords LED; lighting; lighting technology; light emitting diode; firelight LED
Abstract We report on a blue-amber (“firelight”) cluster of light-emitting diodes (LEDs) with extra-low correlated color temperature (~1860 K) optimized for outdoor lighting under mesopic conditions. When compared with common white LEDs, the firelight LED cluster shows considerably reduced indexes of melatonin suppression and skyglow, increased retinal illuminance for elderly people, but a reduced performance of perceiving colors, which, however, can be tolerated at mesopic luminance. In comparison with an almost metameric high-pressure sodium lamp, the cluster exhibits a potentially higher luminous efficacy, similar reaction time and detection threshold of luminance contrasts for achromatic targets, and noticeably improved color discrimination characteristics.
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Language (up) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 1943-0655 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 281
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Author Jou, J.-H.; Hsieh, C.-Y.; Tseng, J.-R.; Peng, S.-H.; Jou, Y.-C.; Hong, J.H.; Shen, S.-M.; Tang, M.-C.; Chen, P.-C.; Lin, C.-H.
Title Candle Light-Style Organic Light-Emitting Diodes Type Journal Article
Year 2013 Publication Advanced Functional Materials Abbreviated Journal Adv. Funct. Mater.
Volume 23 Issue 21 Pages 2750-2757
Keywords organic light emitting diodes; candle light; firelight; OLED; CRI; color rendition
Abstract In response to the call for a physiologically-friendly light at night that shows low color temperature, a candle light-style organic light emitting diode (OLED) is developed with a color temperature as low as 1900 K, a color rendering index (CRI) as high as 93, and an efficacy at least two times that of incandescent bulbs. In addition, the device has a 80% resemblance in luminance spectrum to that of a candle. Most importantly, the sensationally warm candle light-style emission is driven by electricity in lieu of the energy-wasting and greenhouse gas emitting hydrocarbon-burning candles invented 5000 years ago. This candle light-style OLED may serve as a safe measure for illumination at night. Moreover, it has a high color rendering index with a decent efficiency.
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Publisher Place of Publication Editor
Language (up) Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1616301X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 284
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