• Journal of Ecology and Environment
• /
• v.45 no.4
• /
• pp.218-227
• /
• 2021

Background: Artificial light at night has recently been identified as a major factor adversely affecting global insect diversity. Here, we compared the insect diversity in Gwangneung Forest Biosphere Reserve, specifically in the Korea National Arboretum (with no artificial light at night), with that of three nearby urban sites with a gradient of artificial light at night (five locations at each site). We analyzed the effects of the artificial night lighting index, mean annual temperature, and field light intensity (lux) at night on the insect community structure. Results: The urban sites generally exhibited higher species richness and abundance as well as clear indicator species compared with the control site. The size distribution of the collected insects markedly differed between the control and the three urban sites. The abundance of herbivorous and omnivorous insects increased and decreased, respectively, with the increase in light intensity. Species richness of herbivorous and omnivorous insects was likely correlated with the field light intensity at night and artificial night lighting index, respectively. Conclusions: This study demonstrates the association between nighttime environment and marked changes in insect community structure and revealed consequent transition of ecosystem services by changes in trophic group composition.

• Sleep Medicine and Psychophysiology
• /
• v.23 no.2
• /
• pp.53-60
• /
• 2016

Objectives: Exposure to light at night has become pervasive in modern society. The impact of dim artificial light at night (dALAN) exposure on sleep and fatigue is not well recognized. We aim to study the impact of dALAN exposure during sleep on human fatigue. Methods: 30 healthy young male volunteers from 21 to 29 years old were enrolled in the study. They were randomly divided into two groups depending on light intensity (Group A : 5 lux and Group B : 10 lux). Data were gathered from each participant after each night with no light (Night 1) followed by the next night (Night 2) with two different dim light conditions (5 or 10 lux) by means of self-reported fatigue scale. Results: Exposure to dALAN during sleep was significantly associated with increased overall fatigue (F = 19.556, p < 0.001) and ocular discomfort (F = 5.671, p = 0.028). Conclusion: We found that dALAN during sleep likely affects human fatigue in some aspects. These findings indicate that dALAN during sleep exerts a negative effect on human fatigue.

• KIEAE Journal
• /
• v.10 no.2
• /
• pp.71-78
• /
• 2010

Spill light by street lighting is a kind of light pollution creating cozy night atmosphere, interfere visual private and cause insomnia at night. This study was to survey light trespass of the windows in residential buildings. According to outdoor lighting control guidance in Seoul, three different areas were selected to investigate the trespass light to windows. The results were as follows: 37% of the buildings of 386 buildings were influenced by street lighting, and 47% of windows were occurred light trespass. Therefore, the street lighting affected light trespass at night in survey area. The main reasons of light trespass were luminaire type, luminaire pole height, and street width. For protecting the light trespass to windows, it is necessary to non-cutoff fixture to full cutoff fixture by the street width.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.10
• /
• pp.4661-4664
• /
• 2016

Background: Artificial light at night (ALAN) has been linked to increased risk of cancers in body sites like the breast and colorectum. However exposure of ALAN as an environmental risk factor and its relation to cancers in humans has never been studied in detail. Objective: To explore the association of ALAN with all forms of cancers in 158 countries. Materials and Methods: An ecological study encompassing global data was conducted from January to June 2015, with age-standardized rates (ASR) of cancers as the outcome measure. ALAN, in the protected areas, as the exposure variable, was measured with reference to the Protected Area Light Pollution Indicator (PALI) and the Protected Area Human Influence Indicator (PAHI). Pearson's correlations were calculated for PALI and PAHI with ASR of cancers for 158 countries, adjusted for country populations, electricity consumption, air pollution, and total area covered by forest. Stratified analysis was conducted according to the country income levels. Linear regression was applied to measure the variation in cancers explained by PALI and PAHI. Results: PALI and PAHI were positively associated with ASR of all forms of cancer, and also the four most common cancers (p < 0.05). These positive correlations remained statistically significant for PAHI with all forms of cancer, lung, breast, and colorectal cancer after adjusting for confounders. Positive associations of PALI and PAHI with cancers varied with income level of the individual countries. Variation in all forms of cancers, and the four most common cancers explained by PALI and PAHI, ranged from 3.3 - 35.5%. Conclusion: Artificial light at night is significantly correlated for all forms of cancer as well as lung, breast, colorectal, and prostate cancers individually. Immediate measures should be taken to limit artificial light at night in the main cities around the world and also inside houses.

• Journal of Korea Multimedia Society
• /
• v.20 no.12
• /
• pp.1901-1912
• /
• 2017

Traffic lights at night are usually framed in the image as bright regions bigger than the real size due to glow effect. Moreover, the colors of lighting region saturate to white. So it is difficult to distinguish between different traffic lights at night. Many related studies have tried to decrease the glow effect in the process of capturing images. Some studies drastically decreased the shutter time of the camera to reduce the adverse effect by the glow. However, this makes the video too dark. This study proposes a new idea which utilizes the glow effect. It examines the outer radial region of traffic light. It presents an algorithm to discriminate the color of traffic light by the analysis of the outer radial region. The advantage of the proposed method is that it can recognize traffic lights in the image captured by an ordinary black box camera. Experimental results using seven short videos show the performance of traffic light recognition reporting the precision of 96.4% and the recall of 98.2%. These results show that the proposed method is valid and effective.

• Korean Institute of Interior Design Journal
• /
• v.24 no.6
• /
• pp.137-144
• /
• 2015

Light was the symbol of the city's prosperity and culture. People can walk around the city at the night time with safe. Now light is used with beauty and function at the same time. This study is the example how to draw the lighting design concept in specific city and district based on the citizen-minded survey. The citizen-minded survey makes a new chance taking the goodness and characteristics from local city specially and select the site for applying the specific opinion and requirement in the city. The expression of design concept on night landscape design gives the fresh image to the city during the night time. Because people feel the free and dynamic mood in the night landscape lighting, it is very important to set and express the design concept on night landscape design. The result of this study was applied in the Daegu city. In particular, the distribution complex's night landscape lighting in the Daegu was designed with specific concept expression from the citizen-minded survey. Making and expressing the design concept on night landscape design is basic for unity and diversity in the city.

• Journal of The Korean Astronomical Society
• /
• v.37 no.4
• /
• pp.179-184
• /
• 2004

We have developed a wide-field imaging camera system, called WICZO, to monitor light of the night sky over extended period. Such monitoring is necessary for studying the morphology of interplanetary dust cloud and also the time and spatial variations of airglow emission. The system consists of an electric cooler a CCD camera with $60\%$ quantum efficiency at 500nm, and a fish-eye lens with $180^{\circ}$ field of view. Wide field imaging is highly desired in light of the night sky observations in general, because the zodiacal light and the airglow emission extend over the entire sky. This paper illustrates the design of WICZO, reports the result of its laboratory performance test, and presents the first night sky image, which was taken, under collaboration with Byulmaro Observatory, on top of Mt. Bongrae at Yongweol in January, 2004.

• Journal of Platform Technology
• /
• v.10 no.3
• /
• pp.60-68
• /
• 2022

As AI-technology develops, interest in the safety of autonomous driving is increasing. Recently, autonomous vehicles have been increasing, but efforts to solve side effects have been sluggish. In particular, night autonomous vehicles have more problems. This is because the probability of accidents is higher in the night driving environment than in the day environment. There are more factors to consider for self-driving at night. Among these factors, reflection of light or reflected light of lighting may be a fundamental cause of night accidents. Therefore, this study proposes method to reduce accidents and improve safety by reducing reflected light generated by the headlights of opposite vehicles or various surrounding light that appear as an important problem in night autonomous vehicles. Therefore, first, in an image obtained by a sensor of a night autonomous vehicle, illumination reflected light is extracted using reflected light characteristic information, and a color of each pixel using a reflection coefficient is found to reduce a special area generated by geometric characteristics. In addition, we find a new area using only the brightness component of the specular area, define it as Illuminated Reflection Light (IRL), and finally present a method to reduce it. Although the illumination reflection light could not be completely reduce, generally satisfactory results could be obtained. Therefore, it is believed that the proposed study can reduce casualties by solving the problems of night autonomous driving and improving safety.

• Journal of The Korean Astronomical Society
• /
• v.18 no.1
• /
• pp.1-13
• /
• 1985

We present the data of photoelectric photometric observations of BW Vul carried out for four nights during the period of $1982{\sim}1984$. The light curves with asymmetric shape show a stillstand on the ascending branch at phase of ${\phi}{\approx}0.85$ just before the maximum light, and also the ampitude and shape of light curves are changed from night to night. Using all the published data, a new ephemeris of maximum time is derived, in which the period of light variation is $P=0^d.20102977$ and its increasing rate is 2.2 see/century.

• Science of Emotion and Sensibility
• /
• v.20 no.4
• /
• pp.135-142
• /
• 2017

In the present study, we investigated the physiological effects of smartphone use at night when the display luminance and white balance were differently manipulated. Two levels of luminance and two types of white balance were combined to form four types of displays. Subjects were instructed to use smartphones between 23:00 to 01:00 twice a week for two weeks, and for each trial, subjects were given one of the four display types. Melatonin concentration in the saliva, body temperature and heart rate were measured before and after each experiment. The experimental result showed that the low luminance display supported melatonin secretion and thermoregulation compared to the high luminance display. With regard to the white balance, higher melatonin level was observed when using the display that filtered blue light. The low luminance display together with yellowish tint best supported restful sleep at night in terms of every physiological response. This study collectively demonstrates that bright and blue light emitted from smartphone displays adversely affect melatonin secretion, body temperature, and heart rate, and therefore, suggests the use of a display with low luminance or a display that filters blue light for a restful sleep at night.