• Title/Summary/Keyword: nighttime

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TEMPORAL AND SPA TIAL VARIATION OF NIGHTTIME FISHING GROUND DERIVED FROM SATELLITE IMAGERY

  • Kim Sang-Woo;Jeong Hee-Dong;Suh Young-Sang;Go Woo Jin;Jang Lee-Hyun
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.437-440
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    • 2005
  • We examined the relationship between the 50m temperature estimated by remote sensing sea surface temperature (SST) and fishing ground (squid fishing ground) detected by nighttime visible channel defense meteorological satellite program (DMSP) I operational linescan system (OLS) images in the East/Japan Sea during 1993-2000. The results are as follows: The numbers of nighttime fishing boat were distributed the highest in October, and the lowest in April during this study. A nighttime fishing grounds have concentrated in the East Korea Warm Current region, coastal regions of Honshu Island, and Polar front region. Fishing grounds have distributed $11-18^{\circ}C$ of estimated 50m temperature from the satellite data. Relationship between estimated 50m temperature and the distributed fisheries boats showed that the north boundaries of fishing grounds have distributed the temperature of below $12^{\circ}C$ from 1996 to 2000 and that of $13-15^{\circ}C$ during 1993-1995 and 1997-1999. Stable fishing grounds appeared near the Korea/Tsushima Strait from January to March. The center of fishing grounds in spring (April-Jun) have moved to the northward than that in winter, and variations appeared largely in winter. In summer (July-September), center of fishing grounds have formed near the Uleung Island in the south east coast of Korea, and in autumn maximum fishing ground appeared in October, the fishing ground southward from November.

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A study on the Sleep/Activity pattern of normal neonate in Kangwon area (강원도 지역 신생아 수면/활동 양상에 관한 연구)

  • Kwon, Mi-Kyung;Lee, Kyung-Min;Choi, Seon-Jeong;Choi, Sang-Soon
    • Korean Parent-Child Health Journal
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    • v.3 no.2
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    • pp.18-24
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    • 2000
  • The purpose of this research is to investigate Sleep/Activity pattern of normal neonate in Kangwon area. The subjects of this research were 23 normal neonate who visited pediatric clinic of kangneung general hospital from Jun 15, 1999 to August 10, 2000. The instrument of this research was the NCASA. The results of this research were as follows: 1. The mean time of daytime sleep was 8.21 hours. The mean time of nighttime sleep was 5.70 hours. The mean time of total daily sleep was 13.92 hours. The mean time of longest sleep period was 5.02 hours. The mean time of regularity of sleep were daytime 46.59%, nighttime 74.43%, total daily sleep 55.88%. The mean frequency of nighttime wakening was 2.03 times. 2. The each mean time of activity were daytime 7.72 hours, nighttime 2.28 hours, daily total activity 9.99 hours. The mean time of the longest activity period was 6.16 hours. The mean times of feeding frequency were daytime feeding 4.53, nighttime feeding 1.92, total daily feeding 6.45. The mean of regularity of feeding frequency was 65.71%.

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Retrieval of Nighttime Aerosol Optical Thickness from Star Photometry (별 측광을 통한 야간 에어로졸의 광학적 두께 산출)

  • Oh, Young-Lok
    • Atmosphere
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    • v.25 no.3
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    • pp.521-528
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    • 2015
  • In this study star photometry was applied to retrieve aerosol optical thickness (AOT) at night. The star photometry system consisted of small refractor, optical filters, CCD camera, and driving mount and was located in Suwon. The calibration constants were retrieved from the astronomical Langley method but standard deviations of these were more than 10% of the mean values. After the calibration the nighttime AOT was retrieved and cloud-screened in clear six days from 25 Nov. 2014 to 17 Jan. 2015. To estimate the quality of the measurements the nighttime AOT was combined with daytime AOT retrieved from sky-radiometer that was located in Seoul and 17 km away from the star photometry system. In spite of the uncertainty of the calibration constants and the spatial difference of two observation systems, the temporal changes of the nighttime AOT coincided with the daytime. The nighttime ${\AA}ngstr{\ddot{o}}m$ exponent was about 20% lower and more variable than the daytime because of the uncertainty of the calibration constants. If the calibration process is more precise, the combination of star and sun or sky photometry system can monitor the air pollution day and night constantly.

Obstacle Detection in Nighttime Traffic Scenes using IR Images (IR 영상을 이용한 교통영상에서의 야간장애물 검지 기법)

  • 박동렬;박영태
    • Proceedings of the IEEK Conference
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    • 1999.11a
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    • pp.633-636
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    • 1999
  • We present a robust scheme of detecting obstacles such as vehicles, human beings, and other artificial structures that may cause serious traffic accidents in the nighttime driving. Obstacle regions are detected by the evidential reasoning rules that combine the isolated regions obtained by the phase-directed edge-linking and the hot evidence information. Preliminary experimental results show that the performance is robust to nighttime infrared scenes having various types of obstacles

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Daytime and Nighttime Photochemical Reactions of the Pure Oxygen System (순수 산소계의 주간 및 야간 광화학반응)

  • Kwnag Sik Yun
    • Journal of the Korean Chemical Society
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    • v.13 no.4
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    • pp.249-261
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    • 1969
  • Studies of photochemical reactions of the pure oxygen atmosphere are made using reaction rate constants and atmospheric data available in the latest literature. The daytime and nighttime variations in atomic oxygen and ozone are computed, based on three different conditions: 1) photochemical equilibrium, 2) direct integrations of the rate equations with modifications and approximation to the equations, and 3) by numerical integrations. The departure from the photochemical equilibrium concentrations during day and nighttime are discussed by comparing the results obtaind from the three conditions.

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An reproduction algorithm of nighttime road-image for visibility evaluation of headlamps (헤드램프의 시계성 평가를 위한 야간 도로 영상 재현 알고리즘)

  • 이철희;하영호
    • Proceedings of the IEEK Conference
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    • 2000.11d
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    • pp.69-72
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    • 2000
  • This study proposes a new calculation method for generating real nighttime lamp-lit images. In order to improve the color appearance in the prediction of a nighttime lamp-lighted scene, the lamp-lit image is synthesized based on spectral distribution using the estimated local spectral distribution of the headlamps and the surface reflectance of every object. The principal component analysis method is introduced to estimate the surface color of an object, and the local spectral distribution of the headlamps is calculated based on the illuminance data and spectral distribution of the illuminating headlamps. HID and halogen lamps are utilized to create beam patterns and captured road scenes are used as background images to simulate actual headlamp-lit images on a monitor. As a result, the reproduced images presented a color appearance that was very close to a real nighttime road image illuminated by single and multiple headlamps.

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On Study on Chatacteristics of Nocturnal Meteorological Parameter at Mountain Slope (연구노트 산사면에서의 야간 기상요소의 특성에 관한 연구)

  • 전병일;박재림;박현철
    • Journal of Environmental Science International
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    • v.8 no.5
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    • pp.633-637
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    • 1999
  • A series of meterological observation using automation weather station(AWS) carried out to investigate characteristics of nocturnal meteorological parameters for 16~17 June 1998 at Buljeongdong mountain slope, Kyungbuk. Dry temperature at valley was lower than mountain because of high lapse rate at valley, so the strong inversion layer occurrenced at mountain slope for nighttime. Contrary of dry temperature, relative humidity of valley was higher than mountain for nighttime. Wind speed at valley from sunset to next day morning was lower than mountain, but that of valley after sunrise was higher than mountain. Wind direction at valley for all observation time were southeasterlies(SE), that of mountain for nighttime were northeasterlies(NE) or northnorthwesterlies(NNW), and that of mountain after sunrise were irregular. Vapor pressure at valley for all observation time was higher mountain, particularly the difference was high for nighttime.

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Investigation of the Characteristic Nighttime Temperature of Potential Caves on Mars

  • Park, Nuri;Hong, Ik-Seon;Jung, Jongil
    • Journal of Astronomy and Space Sciences
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    • v.39 no.4
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    • pp.141-144
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    • 2022
  • By providing an environment where energetic particles and micrometeorites can not penetrate, caves on Mars may serve as a human shelter in future Mars explorations. More than 1,000 cave entrance candidates have been detected; however, their physical characteristics that can be utilized in detecting more candidates have not been explored in detail. In this paper, we explore the nighttime temperature of 100 cave entrance candidates and their surrounding areas to investigate 1) the nighttime temperature tendencies relative to their surrounding areas and 2) the extent of these temperature differences. We find that 79% of the cave entrance candidates exhibit higher temperatures than the surrounding areas, and 59% show a temperature difference over 20K, suggesting that the cave entrances may generally show higher temperatures than the surrounding areas during the nighttime.

The Correlation of $L_{dn}$ in accordance with the daytime and the nighttime - Focusing on road traffic noise - (주간 및 야간 시간대에 따른 $L_{dn}$의 상관관계 - 도로교통소음을 중심으로 -)

  • Kim, Deuk-Sung;Chang, Seo-Il;Lee, Yeon-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.34-40
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    • 2006
  • The daytime(7 a.m to 10 p.m.) and the nighttime(10 p.m. to 7 a.m.) used to calculate existing $L_{dn}$ is different from the domestic daytime(6 a.m to 10 p.m.) and nighttime(10 p.m. to 6 a.m.) periods. The difference of a time periods makes too difficult for converting measured $L_{eq}$ during daytime($L_d$) and nighttime($L_n$) periods to $L_{dn}$. Thus, it is difficult to directly compare with $L_{dn}$ standard of a foreign country. The pupose of paper is to propose a proper experimental equations that make up for the problems. The data of this paper used road traffic noise data of Auto-Network System(ANS) that generates $L_{eq}$ TNI, $L_{NP}$ for 1 hour. A method of this paper is as follows.(1) The data of ANS converted 24 hour $L_{eq}$ which measured every 1 hour to existing $L_{dn}$ and to $L_{dn}$ of an experimental equations.(2) The existing Lan is compared to results of $L_{dn}$ from experimental equations. The paper proposes a three experimental equations. This paper select an approximate equation that was most similar, to existing $L_{dn}$ out of these equations. When $L_{eq}$ data of different daytime and nighttime periods are converted to $L_{dn}$, an experimental equation of this paper can be used and applied to $L_{dn}$'s calculation.

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GIS Analyst of Fishing Fleet in the East Sea Derived from Nighttime Satellite Images in 1993 (1993년 야간위성영상에서 관측한 동해 어선분포의 GIS에 의한 분석)

  • 김상우
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.6
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    • pp.812-818
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    • 2002
  • Spatio-temporal distributions of nighttime fishing fleet are descirbed with the aid of geographic information system(GIS) technology in the East/Japan Sea, using daily mean composite images of the Defense Meteorological Satellite Program(DMSP) /Operational Linescan System(OLS) in 1993. We selected a study area from $30^{\circ} N to 44^{\circ} N in latitude and from 124^{\circ} E to 142^{\circ}$ E in longitude in order to describe the monthly and seasonal changes of nighttime fishing fleet. The GIS software package Image Analyst (ArcView 3) are used to analyze spatio-temporal distributions of fishing nut. And the OLS images of nighttime visible band provide useful information about the spatio-temporal distribution of the fishing nut. Density areas of nighttime fishing fleet are around Tsushima/korea Strait. the east coast of the Korea Peninsula, the coast of Honshu, and around Yamato Bank.