scholarly journals Mobile mapping of night-time road environment lighting conditions

2018 ◽  
Vol 26 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Matti Vaaja ◽  
Mikko Maksimainen ◽  
Juho-Pekka Virtanen ◽  
Antero Kukko ◽  
Ville Lehtola ◽  
...  
Keyword(s):  
Night Time ◽  
Mobile Mapping ◽  
Lighting Conditions

Four minutes might not be enough for light colour temperature to affect sleepiness, mental effort, and light ratings

2018 ◽  
Vol 51 (7) ◽  
pp. 1128-1138
Author(s):  
R Lasauskaite ◽  
EM Hazelhoff ◽  
C Cajochen
Keyword(s):  
Task Performance ◽  
Cardiovascular Response ◽  
Cognitive Task ◽  
Memory Task ◽  
Subjective Ratings ◽  
Night Time ◽  
Colour Temperature ◽  
Lighting Conditions ◽  
Effort Mobilization ◽  
Short Memory

Light exerts a number of non-image-forming effects that are mostly apparent during night-time but can also been seen during daytime. Recently, we have shown that exposure to light of higher colour temperature prior to performing a cognitive task leads to a weaker effort-related cardiovascular response compared to exposure to light of lower colour temperature. This present study tested if presenting light of different colour temperatures during rather than before the task performance would lead to equivalent changes in effort mobilization. Participants performed a modified Sternberg short-memory task for eight minutes as lighting conditions were adjusted to one of four experimental lighting conditions (2800 K, 4000 K, 5000 K, or 6500 K) after the first four minutes, for the remaining four minutes. We predicted that effort-related cardiovascular response would strengthen with decreasing colour temperature. The results, however, did not follow this predicted pattern. No significant effects of lighting conditions on subjective measures were observed. Therefore, we conclude that four minutes might not be enough for light colour temperature to induce changes in effort-related cardiovascular response or affect subjective ratings of sleepiness and lighting.

scholarly journals Night-time Lookout Duty: The Role of Ambient Light Levels and Dark Adaptation

2012 ◽  
Vol 65 (4) ◽  
pp. 589-602 ◽  
Author(s):  
Tony Wynn ◽  
Peter A. Howarth ◽  
Bert R. Kunze
Keyword(s):  
Dark Adaptation ◽  
Probability Of Detection ◽  
Working Environment ◽  
Ambient Light ◽  
Night Time ◽  
Lighting Conditions ◽  
Light Levels ◽  
Ambient Lighting ◽  
Small Craft

The aim of this research was to clarify and quantify the demands of the working environment and watch-keeping regime for large commercial ships in relation to dark adaptation. The night lookout task requires the identification of the relatively bright navigational lights of other ships against the dark background of the sky and sea. The probability of detection is determined by the ambient lighting conditions on the bridge and the dark adapted state of vision. Light levels were such that threshold sensitivity (after 15 minutes) was reduced by around 2 log units in comparison to complete darkness. This has implications for the effective range of navigational lights at sea as defined in regulations. The intensity and position of navigation lights on larger vessels is such that the sensitivity of the eye under typical bridge conditions is likely to be sufficient for their visibility to be acceptable. This may not be the case for less well lit small craft.

scholarly journals APPROACHES FOR MAPPING NIGHT-TIME ROAD ENVIRONMENT LIGHTING CONDITIONS

2020 ◽  
Vol V-1-2020 ◽  
pp. 199-205
Author(s):  
M.T. Vaaja ◽  
M. Maksimainen ◽  
M. Kurkela ◽  
J.-P. Virtanen ◽  
T. Rantanen ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Measurement Techniques ◽  
Point Clouds ◽  
Future Research ◽  
3D Measurement ◽  
Night Time ◽  
Road Lighting ◽  
Lighting Conditions ◽  
Potential Applications ◽  
2D Imaging

Abstract. The integration of the 3D measurement techniques with luminance imaging has increased the potential for mapping night-time road lighting conditions. In this study, we present selected static and mobile approaches for the purpose. The measurement methods include conventional 2D imaging luminance photometry and the integration of the luminance imaging with terrestrial and mobile laser scanning. In addition, we present our initial experiences with performing integrated luminance mapping and photogrammetric reconstruction from drone imagery. All of the presented methods require that the camera is calibrated with a reference luminance source. Our results show the results of luminance calibration and feasibility of 3D luminance point clouds for evaluating road surface luminances. In addition, we discuss the other potential applications, limitations and future research.

scholarly journals Hydroponic Minituber Production in Growth Room Conditions and Carry-Over Effects of the Technique on Produced Minitubers

2016 ◽  
Vol 9 (1) ◽  
pp. 41 ◽  
Author(s):  
Elina Virtanen ◽  
Jussi Tuomisto
Keyword(s):  
Night Time ◽  
Van Gogh ◽  
Lighting Conditions ◽  
In Vitro Plantlets ◽  
Growing Medium ◽  
Carry Over ◽  
Foliage Development ◽  
Indoor Conditions ◽  
Better Than

<p>The production of minitubers was implemented with a hydroponic technique in growth rooms and the carry-over effects of the technique on the characteristics of minitubers were studied. As a comparison, minitubers from in vitro plantlets were grown in a peat-based growing medium. The results show that hydroponic production of minitubers is successful in indoor conditions with the cultivars Desiree, Van Gogh and Asterix, when day-time growing temperatures of 19.4 <sup>o</sup>C-26.0 <sup>o</sup>C and night-time temperatures of 17.5 <sup>o</sup>C-22.6 <sup>o</sup>C were used. Photosynthetically active illumination was adequate at 2383-2509 umol m<sup>-2</sup>s<sup>-1</sup>; lighting conditions consisted of 14/10-hour day/night cycles.</p><p>The cultivars Desiree and Van Gogh developed their first tuber three weeks faster than Asterix, and the minituber yield was 4.5 per plant for Desiree, 7.5 for Van Gogh and 4.0 for Asterix. When a peat-based growing medium was used, minituber yields were almost the same but the size of the minitubers was smaller than that of hydroponically produced minitubers. The results of the carry-over experiments showed that conventionally produced minitubers emerged faster, and in terms of foliage development and yielding capacity performed better than hydroponically produced minitubers.</p>

Modulation of gonadal activity by timed injections of melatonin in pinealectomized or intact ferrets kept under two photoperiods

1982 ◽  
Vol 93 (2) ◽  
pp. 211-222 ◽  
Author(s):  
D. S. Carter ◽  
J. Herbert ◽  
Pamela M. Stacey
Keyword(s):  
Neural Mechanisms ◽  
Reproductive Status ◽  
Night Time ◽  
Once Daily ◽  
Timing Mechanism ◽  
Lighting Conditions ◽  
Gonadal Activity ◽  
Environmental Lighting ◽  
Endogenous Melatonin ◽  
The Way

These experiments investigated the way that the effects of melatonin on gonadal activity of ferrets depended upon either reproductive status or environmental lighting conditions. Melatonin (1 mg/day) injected once daily 8 h into the photoperiod prevented the retiming of oestrus by long photoperiods; oestrus occurred in animals treated in this way at the same time as in controls kept under short non-stimulatory photoperiods of 8 h light: 16 h darkness (8L : 16D). This suggests that the 'intrinsic' timing mechanism was not altered by melatonin. Melatonin injected daily into oestrous ferrets terminated oestrus prematurely when the injection was given either 8 or 14 h after the onset of the photoperiod in animals kept under either long (14L : 10D) or short (8L : 16D) photoperiods, though injections given 14 h after onset were more potent in long (but not short) light periods. Melatonin was equally effective in driving pinealectomized ferrets out of oestrus as it was in intact animals. Melatonin could also induce as well as terminate oestrus in ferrets, but only if injections were discontinued. Thus, shifting the time of two daily injections from 8 and 11 h after 'lights on' to 14 and 17 h was ineffective, but withdrawal of melatonin from anoestrous ferrets (pinealectomized or intact) reliably induced oestrus 4–6 weeks later, irrespective of the lighting conditions. Withdrawal of oil injections had no effect. These experiments suggest that melatonin acts on the neural mechanisms resetting the timing of oestrus, rather than by a direct 'anti-gonadotrophic' effect. Furthermore, the effect of changes in duration of photoperiod could not be replicated by simply changing the time of melatonin injections to correspond with the presumed night-time surge of endogenous melatonin. Some of the effects of melatonin on retiming oestrus can only be expressed in the absence of melatonin itself.

scholarly journals Artificial Light Sources in Roman, Byzantine, and Post- Byzantine Eras: An Evaluation of their Performance

Chronos ◽  
2018 ◽  
Vol 32 ◽  
pp. 119-132 ◽  
Author(s):  
Dorina Moullou ◽  
Lambros T Doulos ◽  
Frangiskos V Topalis
Keyword(s):  
Artificial Light ◽  
Light Sources ◽  
Night Time ◽  
Lighting Conditions

The assessment of the performance of ancient lighting devices may provide scholars with valuable information on the lighting conditions that existed in ancient houses, and on the level of optical comfort created by the use of those devices. Consequently, it also provides scholars with valuable information on the feasibility of activities performed during night time. This paper focuses on the investigation of the performance of lighting devices, namely lamps and candles, used in Greece during the Roman, Byzantine, and Post-Byzantine eras. At the same time, we provide non-lighting specialists (e.g. archaeologists) with the tool to assess the performance of the lighting devices they study, as well as to estimate the amount of light emitted on a surface of interest.

CHARACTERISATION OF LUMINESCENT ROAD MARKINGS

2021 ◽  
Author(s):  
C. Villa ◽  
R. Bremond ◽  
F. Eymond ◽  
E. Saint-Jacques
Keyword(s):  
Light Pollution ◽  
Laboratory Measurements ◽  
Night Time ◽  
The Road ◽  
Lighting Conditions ◽  
Visibility Distance ◽  
On The Road ◽  
The Cost ◽  
Road Marking ◽  
Traffic Measurements

Photoluminescent paints for road marking have been evaluated through laboratory measurements and visibility computations. The luminance decay in the dark was measured after constant excitation during at least six hours. To study the effect of night-time lighting conditions, luminance was also measured under a constant low illumination simulating moon and light pollution, and a periodic lighting simulating automotive traffic. Measurements were also carried out on luminescent road markings applied in a full scale mock up. Then, possible uses and limits of photoluminescent road markings were investigated through visibility computations based on the COST 331 model. Findings suggest that luminescent road markings could strengthen the visual guidance of drivers on the road with traffic by increasing the visibility distance beyond the range of the headlamps during the first few hours of the night, but it depends on the night-time illumination level.

scholarly journals UAV Photogrammetry under Poor Lighting Conditions—Accuracy Considerations

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3531
Author(s):  
Pawel Burdziakowski ◽  
Katarzyna Bobkowska
Keyword(s):  
Digital Camera ◽  
Image Data ◽  
Light Sources ◽  
Night Time ◽  
Distortion Parameter ◽  
Lighting Conditions ◽  
Reprojection Error ◽  
Typical Day ◽  
Intrinsic Orientation ◽  
Poor Lighting

The use of low-level photogrammetry is very broad, and studies in this field are conducted in many aspects. Most research and applications are based on image data acquired during the day, which seems natural and obvious. However, the authors of this paper draw attention to the potential and possible use of UAV photogrammetry during the darker time of the day. The potential of night-time images has not been yet widely recognized, since correct scenery lighting or lack of scenery light sources is an obvious issue. The authors have developed typical day- and night-time photogrammetric models. They have also presented an extensive analysis of the geometry, indicated which process element had the greatest impact on degrading night-time photogrammetric product, as well as which measurable factor directly correlated with image accuracy. The reduction in geometry during night-time tests was greatly impacted by the non-uniform distribution of GCPs within the study area. The calibration of non-metric cameras is sensitive to poor lighting conditions, which leads to the generation of a higher determination error for each intrinsic orientation and distortion parameter. As evidenced, uniformly illuminated photos can be used to construct a model with lower reprojection error, and each tie point exhibits greater precision. Furthermore, they have evaluated whether commercial photogrammetric software enabled reaching acceptable image quality and whether the digital camera type impacted interpretative quality. The research paper is concluded with an extended discussion, conclusions, and recommendation on night-time studies.

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