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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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ISSN 0035-8711 ISBN Medium (up)
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 Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0272-4944 ISBN Medium (up)
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 Volume Series Issue Edition
ISSN 1477-1535 ISBN Medium (up)
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 Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN 1943-0655 ISBN Medium (up)
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 281
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Author Aubé, M.; Roby, J.; Kocifaj, M.
Title Evaluating potential spectral impacts of various artificial lights on melatonin suppression, photosynthesis, and star visibility Type Journal Article
Year 2013 Publication PloS one Abbreviated Journal PLoS One
Volume 8 Issue 7 Pages e67798
Keywords Humans; *Light; Lighting/methods; Melatonin/*metabolism; Photosynthesis/*radiation effects; Plant Development/radiation effects; blue light; circadian disruption
Abstract Artificial light at night can be harmful to the environment, and interferes with fauna and flora, star visibility, and human health. To estimate the relative impact of a lighting device, its radiant power, angular photometry and detailed spectral power distribution have to be considered. In this paper we focus on the spectral power distribution. While specific spectral characteristics can be considered harmful during the night, they can be considered advantageous during the day. As an example, while blue-rich Metal Halide lamps can be problematic for human health, star visibility and vegetation photosynthesis during the night, they can be highly appropriate during the day for plant growth and light therapy. In this paper we propose three new indices to characterize lamp spectra. These indices have been designed to allow a quick estimation of the potential impact of a lamp spectrum on melatonin suppression, photosynthesis, and star visibility. We used these new indices to compare various lighting technologies objectively. We also considered the transformation of such indices according to the propagation of light into the atmosphere as a function of distance to the observer. Among other results, we found that low pressure sodium, phosphor-converted amber light emitting diodes (LED) and LED 2700 K lamps filtered with the new Ledtech's Equilib filter showed a lower or equivalent potential impact on melatonin suppression and star visibility in comparison to high pressure sodium lamps. Low pressure sodium, LED 5000 K-filtered and LED 2700 K-filtered lamps had a lower impact on photosynthesis than did high pressure sodium lamps. Finally, we propose these indices as new standards for the lighting industry to be used in characterizing their lighting technologies. We hope that their use will favor the design of new environmentally and health-friendly lighting technologies.
Address Departement de physique, Cegep de Sherbrooke, Sherbrooke, Quebec, Canada. martin.aube@cegepsherbrooke.qc.ca
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-6203 ISBN Medium (up)
Area Expedition Conference
Notes PMID:23861808; PMCID:PMC3702543 Approved no
Call Number IDA @ john @ Serial 282
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