• 제목/요약/키워드: Light at night

검색결과 287건 처리시간 0.021초

Changes in nocturnal insect communities in forest-dominated landscape relevant to artificial light intensity

  • Lee, Hakbong;Cho, Yong-Chan;Jung, Sang-Woo;Kim, Yoon-Ho;Lee, Seung-Gyu
    • Journal of Ecology and Environment
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    • 제45권4호
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    • pp.218-227
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    • 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.

야간 수면 중 약한 인공 빛 노출이 피로도에 미치는 영향 (Impact of Dim Artificial Light at Night (dALAN) Exposure during Sleep on Human Fatigue)

  • 조아름;조철현;윤호경;문정호;이헌정;김린
    • 수면정신생리
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    • 제23권2호
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    • pp.53-60
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    • 2016
  • 목 적 : 야간 빛 노출은 현대 사회에서 만연해 있으나 야간 수면 중 약한 빛 노출(dim artificial light at night, dALAN)이 피로도에 미치는 영향은 잘 인지되고 있지 않다. 본 연구에서는 수면 중 약한 빛 노출이 인간의 피로도에 어떠한 영향을 주는가를 살펴보고자 하였다. 방 법 : 21세에서 29세까지의 건강한 남성 지원자 총 30명을 연구에 모집하였다. 그들은 빛 강도에 따라 두 그룹(Group A : 5 lux와 Group B : 10 lux)으로 무작위 배정되었다. 연구 결과 자료는 빛 노출이 없는 밤(Night 1)과 두 가지 다른 약한 빛(5 혹은 10 lux)에 노출된 밤(Night 2) 다음 날 자가 보고된 피로도 척도를 통해 수집하였다. 결 과 : 야간 수면 중 약한 빛 노출은 전반적인 피로도(F = 19.556, p < 0.001)와 안구 불편감(F = 5.671, p = 0.028)의 증가와 유의하게 연관성이 있었다. 결 론 : 본 연구팀에서는 야간 수면 중 약한 빛 노출이 인간의 피로도에 일부 측면에서 영향을 준다는 것을 확인하였다. 이러한 결과들은 야간 수면 중 약한 빛 노출이 인간의 피로도에 부정적인 영향을 준다는 것을 의미한다.

주거지역에서 가로조명에 의한 침입광발생 분석 (A Field Investigation on Light Trespass of Residential Buildings by Street Lighting)

  • 하나;김정태
    • KIEAE Journal
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    • 제10권2호
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    • pp.71-78
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    • 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.

Artificial Light at Night and Cancer: Global Study

  • Al-Naggar, Redhwan A.;Anil, Shirin
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권10호
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    • pp.4661-4664
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    • 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.

야간 영상에서의 빛 번짐 현상을 이용한 교통신호등 인식 (Traffic Light Recognition Based on the Glow Effect at Night Image)

  • 김민기
    • 한국멀티미디어학회논문지
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    • 제20권12호
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    • pp.1901-1912
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    • 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.

시민의식조사를 통한 도시 야간경관디자인 컨셉 표현 (The Expression of Design Concept on Night Landscape through the Citizen-Minded Survey)

  • 김소희
    • 한국실내디자인학회논문집
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    • 제24권6호
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    • pp.137-144
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    • 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.

DEVELOPMENT OF WIDE-FIELD IMAGING CAMERA FOR ZODIACAL LIGHT OBSERVATION

  • KWON S. M.;HONG S. S.;SHIN K. J.
    • 천문학회지
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    • 제37권4호
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    • pp.179-184
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    • 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.

야간 자율주행 안전성 향상을 위한 조명반사광 감소에 관한 기초연구 (A Basic Study on the Reduction of Illuminated Reflection for improving the Safety of Self-driving at Night)

  • 박창민
    • Journal of Platform Technology
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    • 제10권3호
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    • pp.60-68
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    • 2022
  • AI 기술이 발전함에 따라 자율주행의 안전성에 관한 관심이 대두되고 있다. 최근, 자율주행의 차량이 증가하고 있지만 그에 대한 부작용을 해소하기 위한 노력은 다소 부진한 실정이다. 특히, 야간에 운행되는 자율주행 차량은 더욱 많은 문제들을 안고 있다. 운행의 다양한 환경에서 야간 주행의 환경은 매우 중요한 요소이다. 이에, 본 연구에서는 야간 자율주행 차량에서 핵심적인 문제점으로 부상하고 있는 반대 차량의 전조등 또는 주위 다양한 조명에 의해 발생되는 반사광을 감소시키는 방안을 제안한다. 이를 위하여, 먼저, 야간 주행 중에 센서에 의해 획득한 영상에서 반사광 특성 정보를 활용하여 조명 반사광을 추출한 후, 반사계수를 활용한 각 픽셀의 색상을 찾아 specular 영역을 감소한다. 그 후 영역의 밝기성분만을 이용한 새로운 영역을 찾아 최종적으로 이를 감소하는 방안을 제시한다. 조명 반사광을 완벽히 감소할 수는 없지만 대체적으로 만족할 만한 결과를 얻을 수 가 있었다. 따라서 제안된 연구 방법이 야간에서의 자율주행에서 다양한 단점 및 문제들을 해결하고 사고를 줄이는 방법에 기여할 것으로 사료된다.

PHOTOMETRIC OBSERVATIONS OF BW VUL

  • Jung, Jae-Hoon;Lee, See-Woo
    • 천문학회지
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    • 제18권1호
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    • pp.1-13
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    • 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.

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Smartphone Use at Night Affects Melatonin Secretion, Body Temperature, and Heart Rate

  • Na, Nooree;Choi, Hojun;Jeong, Kyeong Ah;Choi, Kyungah;Choi, Kyungsun;Choi, Chulhee;Suk, Hyeon-Jeong
    • 감성과학
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    • 제20권4호
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    • pp.135-142
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    • 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.