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| Author | Luo, Wei (ed) | ||||
| Title | Outdoor lighting – Mesopic photometry, adaptation conditions and user preferences in pedestrian way lighting | Type | Book Whole | ||
| Year | 2014 | Publication | Abbreviated Journal | ||
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| Abstract | The starting point of this work is to review the current recommendations and criteria of road and pedestrian way lighting. At present, the emphasis of traffic safety, the increasing energy costs, and improvements in mesopic photometry have led to new discussions about the accuracy of the recommendations for road lighting. Sufficient road lighting is generally based on the lighting requirements given in different lighting classes. For road lighting, the value of 2 cd/m2 is recommended as the minimum average road surface luminance for the highest lighting class in the CIE and CEN publications. The basis of the average road surface luminance for the lower lighting classes is unknown and lacks experimental works. Moreover, the experimental set-ups of the studies conducted in the 1930s and 1950s do not meet the conditions of motor traffic lighting nowadays. They also have deficiencies in the number and age distributions of the subjects. The values of the average horizontal illuminances of the pedestrian way lighting recommendations are based on studies conducted in the 1970s and 1980s. However, no information exists on how the recommended illuminance values are derived for the different lighting classes. The current recommendations for outdoor lighting are based on photopic photometry, this is daylight visibility conditions. In outdoor lighting, the luminances are in the mesopic range. The CIE recommended system for mesopic photometry should be used in providing recommendations and criteria for both road and pedestrian way lighting. Before implementing mesopic photometry, the adaptation luminance of the road users should be known. This study examined the adaptation conditions of pedestrians based on eye-tracking measurements. A case study in a pedestrian way was conducted in Chongqing of China. The study is related to the currently ongoing task of the CIE JCT-1 Implementation of CIE 191 System for Mesopic Photometry in Outdoor Lighting, which is to investigate adaptation and viewing conditions and define visual adaptation fields in outdoor lighting. The case study consisted of eye-tracking measurements and subjective evaluations of the lighting conditions. It was found that the eye-fixation areas and locations were around a central area of the road surface in the horizontal level but spread over a wider area in the vertical level. The subjective importance of facial recognition depends on the specific visual tasks at different light levels in a pedestrian way. The results also suggest that further studies using an eye-tracking system could combine eye-fixation data with pupil size and luminance data. This would help in further analysis of visual adaptation fields of the road users. |
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| Address | Department of Electrical Engineering and Automation, Aalto University, Finland | ||||
| Corporate Author | Thesis | Ph.D. thesis | |||
| Publisher | Place of Publication | Editor | Luo, Wei | ||
| Language | Summary Language | Original Title | |||
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| Area | Expedition | Conference | |||
Notes  |
Approved | no | |||
| Call Number | IDA @ john @ | Serial | 340 | ||
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| Author | Kayaba, M.; Iwayama, K.; Ogata, H.; Seya, Y.; Tokuyama, K.; Satoh, M. | ||||
| Title | Drowsiness and low energy metabolism in the following morning induced by nocturnal blue light exposure | Type | Journal Article | ||
| Year | 2013 | Publication | Sleep Medicine | Abbreviated Journal | Sleep Medicine |
| Volume | 14 | Issue | Pages | e166-e167 | |
| Keywords | blue light; light exposure; light at night; circadian disruption; drowsiness; melatonin; metabolism; sleep | ||||
| Abstract | Introduction Evening light exposure debilitates the circadian rhythm and elicits sleep disturbance. Blue light peak wavelengths, around 460 nm, suppress melatonin secretion via the non-image-forming system. The effects of nocturnal blue light exposure on sleep have been reported to be specific but rather small (Münch, 2008). This study was designed to assess the effect of nocturnal blue light exposure on sleep and energy metabolism until noon the next day. Materials and methods Nine healthy male volunteers aged between 21 and 25 participated in this study which had a balanced cross-over design with intrasubject comparisons. After 2 h dark adaptation, the subjects were exposed to blue light or no light for 2 h. The peak wavelength of the blue LED was 465 nm, and the horizontal irradiance of the blue light at the height of eye was at 7.02fÊW/cm2. Sleep was recorded polysomnographically, and energy metabolism was measured with a whole body indirect calorimeter. Results There were no significant differences in sleep architecture and energy metabolism during the night. However, dozing (stages 1 and 2) was significantly higher (26.0 < 29.4 vs 6.3 < 8.1 min, P < 0.05), and energy expenditure, O2 consumption, CO2 production and the thermic effect of food (increase in energy expenditure after breakfast) were significantly lower the following morning in the blue light exposure subjects. Conclusion Contrary to our expectation, sleep architecture and energy metabolism during sleep were not affected by evening exposure to blue light. It might be due to our milder intervention by which subjects in a sitting position did not gaze at the light source set on the ceiling, while the subjects in previous studies directly received brighter light via custom built goggles (Cajochen, 2005; Münch, 2008) or gazed at a light source under the influence of mydriatic agents to dilate pupils (Brainard, 2001). New findings of the present study were that dozing (stages 1 and 2) was significantly increased, and energy metabolism was significantly lower the following morning in blue light exposed subjects. This suggests that modulation of the circadian rhythm is affected by nocturnal blue light exposure and the effect continues in the following daytime even if the intervention was mild. |
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| Address | University of Tsukuba, Graduate School of Comprehensive Human Sciences, Japan | ||||
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| ISSN | 1389-9457 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes |
Approved | no | |||
| Call Number | IDA @ john @ | Serial | 349 | ||
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| Author | Lin, Y.; Liu, Y.; Sun, Y.; Zhu, X.; Lai, J.; Heynderickx, I. | ||||
| Title | Model predicting discomfort glare caused by LED road lights | Type | Journal Article | ||
| Year | 2014 | Publication | Optics Express | Abbreviated Journal | Opt. Express |
| Volume | 22 | Issue | 15 | Pages | 18056 |
| Keywords | LED; LED lighting; glare; road safety; traffic | ||||
| Abstract | To model discomfort glare from LED road lighting, the effect of four key variables on perceived glare was explored. These variables were: the average glare source luminance (Lg), the background luminance (Lb), the solid angle of the glare source from the perspective of the viewer; and the angle between the glare source and the line of sight. Based on these four variables 72 different light conditions were simulated in a scaled experimental set-up. Participants were requested to judge the perceived discomfort glare of these light conditions using the deBoer rating scale. All four variables and some of their interactions had indeed a significant effect on the deBoer rating. Based on these findings, we developed a model, and tested its general applicability in various verification experiments, including laboratory conditions as well as real road conditions. This verification proved the validity of the model with a correlation between measured and predicted values as high as 0.87 and a residual deviation of about 1 unit on the deBoer rating scale. These results filled the gap in estimating discomfort glare of LED road lighting and clarified similarities of and differences in discomfort glare between LED and traditional light sources. | ||||
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| Series Volume | Series Issue | Edition | |||
| ISSN | 1094-4087 | ISBN | Medium | ||
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| Notes |
Approved | no | |||
| Call Number | IDA @ john @ | Serial | 351 | ||
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| Author | Poulin, C.; Bruyant, F.; Laprise, M.-H.; Cockshutt, A.M.; Marie-Rose Vandenhecke, J.; Huot, Y. | ||||
| Title | The impact of light pollution on diel changes in the photophysiology of Microcystis aeruginosa | Type | Journal Article | ||
| Year | 2014 | Publication | Journal of Plankton Research | Abbreviated Journal | Journal of Plankton Research |
| Volume | 36 | Issue | 1 | Pages | 286-291 |
| Keywords | light pollution; Microcystis aeruginosa; Cyanobacteria; diel cycles; biology; plankton | ||||
| Abstract | Assessing the effect of light pollution, Microcystis aeruginosa was grown with and without low levels of night lighting. Significant differences were observed between the treatments in the maximum quantum yield of charge separation, the intracellular chlorophyll a concentration, the functional absorption cross-section of photosystem II, the number of Rubisco per cell and per chlorophyll a, the number of photosystem I per chlorophyll a, and the chlorophyll a fraction not bound to the photosystems and IsiA. | ||||
| Address | Departement de Geomatique Appliquee, Universite de Sherbrooke, Sherbrooke, QC J1K 2R1, Canada | ||||
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| Publisher | Oxford Journals | Place of Publication | Editor | ||
| Language | English | Summary Language | English | Original Title | |
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| Series Volume | Series Issue | Edition | |||
| ISSN | 0142-7873 | ISBN | Medium | ||
| Area | Expedition | Conference | |||
| Notes |
Approved | no | |||
| Call Number | IDA @ john @ | Serial | 352 | ||
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| Author | Dunnett, O, | ||||
| Title | Contested landscapes: the moral geographies of light pollution in Britain | Type | Journal Article | ||
| Year | 2014 | Publication | Cultural Geographies | Abbreviated Journal | Cultural Geographies |
| Volume | 22 | Issue | 4 | Pages | 619-636 |
| Keywords | Light pollution; geography; darkness; moral geographies; urbanization | ||||
| Abstract | This paper considers the concept of light pollution and its connections to moral geographies of landscape in Britain. The paper aims to provide a greater understanding of light pollution in the present day, where the issue connects to policy debates about energy efficiency, crime, health, ecology and night time aesthetics, whilst also engaging with new areas of research in cultural geography. The main sources of investigation are the Campaign to Protect Rural England and the British Astronomical Association’s Campaign for Dark Skies (est. 1990). Using interviews, archival and textual analysis, the paper examines this anti-light-pollution lobby, looking at the lead-up to the formation of the Campaign as well as its ongoing influence. A moral geography of light pollution is identified, drawing on two interconnected discourses – a notion of the ‘astronomical sublime’ and the problem of urbanization. Whilst the former is often invoked, both through visual and linguistic means, by anti-light pollution campaigners, the latter is characterized as a threat to clear night skies, echoing earlier protests against urban sprawl. Complementing a growing area of research, the geographies of light and darkness, this paper considers the light pollution lobby as a way of investigating the fundamental relationship between humankind and the cosmos in the modern age. | ||||
| Address | School of Geography, Archaeology and Palaeoecology, Elmwood Avenue, Belfast BT7 1NN, UK | ||||
| Corporate Author | Thesis | ||||
| Publisher | SAGE | Place of Publication | Editor | ||
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| Notes |
Approved | no | |||
| Call Number | IDA @ john @ | Serial | 353 | ||
| Permanent link to this record | |||||