• 제목/요약/키워드: Sky condition

검색결과 130건 처리시간 0.027초

MODIS 적외채널 배경 밝기온도차를 이용한 동북아시아 황사 탐지 (Detection of Yellow Sand Dust over Northeast Asia using Background Brightness Temperature Difference of Infrared Channels from MODIS)

  • 박주선;김재환;홍성재
    • 대기
    • /
    • 제22권2호
    • /
    • pp.137-147
    • /
    • 2012
  • The technique of Brightness Temperature Difference (BTD) between 11 and $12{\mu}m$ separates yellow sand dust from clouds according to the difference in absorptive characteristics between the channels. However, this method causes consistent false alarms in many cases, especially over the desert. In order to reduce these false alarms, we should eliminate the background noise originated from surface. We adopted the Background BTD (BBTD), which stands for surface characteristics on clear sky condition without any dust or cloud. We took an average of brightness temperatures of 11 and $12{\mu}m$ channels during the previous 15 days from a target date and then calculated BTD of averaged ones to obtain decontaminated pixels from dust. After defining the BBTD, we subtracted this index from BTD for the Yellow Sand Index (YSI). In the previous study, this method was already verified using the geostationary satellite, MTSAT. In this study, we applied this to the polar orbiting satellite, MODIS, to detect yellow sand dust over Northeast Asia. Products of yellow sand dust from OMI and MTSAT were used to verify MODIS YSI. The coefficient of determination between MODIS YSI and MTSAT YSI was 0.61, and MODIS YSI and OMI AI was also 0.61. As a result of comparing two products, significantly enhanced signals of dust aerosols were detected by removing the false alarms over the desert. Furthermore, the discontinuity between land and ocean on BTD was removed. This was even effective on the case of fall. This study illustrates that the proposed algorithm can provide the reliable distribution of dust aerosols over the desert even at night.

옥상공간의 태양광 자원 해석을 통한 PV 시스템 및 녹화식재에 대한 적지조건분석 (The Analysis of Optimal Site Condition for Photovoltaic System and Green Roof Planting through Sunlight Component Simulation of Rooftop Area)

  • 김태한;박대근;권지영
    • 한국환경복원기술학회지
    • /
    • 제16권4호
    • /
    • pp.27-40
    • /
    • 2013
  • These day morden cities have serious climatic problems due to enviornmental load caused by excessive development of urbanization. As technological improvement to answer to various ecological disasters and climate changes are also called on the field of construction, inter-disciplinary studies linked to the estabilishment of sustainable energy generation systems and enviornmental control is needed in a consilient point of view. This study aims to analyse optimal site conditions for photovoltaic system and green roof planting through solar radiation simulation in a integrated perspective. In so doing, it seeks to proffer basic study for developing a sound use of roof area that is sustainable in environmental and resources aspects. A computer simulation showed that, in the case of total seasonal solar radiation, summer season resulted 312.5kWh in 35% of total annual solar radiation. This season indicated the lowest radiation rate of the year for direct sunlight in 45.8% of total seasonal solar radiation. Due to such solar radiation simulation, at the largest optimal planting area, Glechoma hederacea var. longituba secured $719.16m^2$ of gross roof area.

다중세션 공동저작 환경에서의 충돌 없는 객체 공유를 위한 대표의장 방식의 플로어 제어 (The Chair-of-Chair-Guided Floor Control for Sharing Objects without Collision in a Multi-Session Collaborative Authoring Environment)

  • 신성운;오삼권
    • 정보처리학회논문지A
    • /
    • 제12A권5호
    • /
    • pp.433-440
    • /
    • 2005
  • 많은 저작자들이 협력하여 작업을 수행할 수 있는 공동저작 시스템에서는 저작을 위해 객체들을 공유하는 일들이 참여 저작자들 간에 빈번히 발생한다. 따라서 객체 액세스를 위한 경쟁을 최소화하고 객체들의 배타적 사용을 보장해 주는 플로어 제어가 필요하다. 플로어(floor)란 공동저작 참여자에게 부여되는 한 공유자원에 대한 임시 사용 권한이다 단일세션 환경을 위한 플로어 제어 기법들은 여러 문헌에서 찾아 볼 수 있으나 다중세션 환경을 위한 기법들은 거의 찾아 볼 수가 없다. 다중 세션 환경에서는 한 객체가 여러 세션에서 동시에 공유될 수 있다. 본 논문은 다중 세션 환경에서의 객체 공유로 인한 문제들의 해결을 위해 대표의장(chair-of-chair) 방식의 플로어 제어 기법을 제안한다. 기존의 의장형 방식을 확장한 이 방식에는 세션 의장들 중에서 선출된 대표의장이 존재한다.

지상 및 위성 고분해 적외스펙트럼 센서에서 관측된 황사 특성 (Infrared Spectral Signatures of Dust by Ground-based FT-IR and Space-borne AIRS)

  • 이병일;손은하;오미림;김윤재
    • 대기
    • /
    • 제19권4호
    • /
    • pp.319-329
    • /
    • 2009
  • The intensive dust observation experiment has been performed at Korea Global Atmosphere Watch Center (KGAW) in Anmyeon, Korea during each spring season from 2007 to 2009. Downward and upward hyper-spectral spectrums over the dust condition were measured to understand the hyper-spectral properties of Asian dust using both ground-based Fourier Transform Infrared Spectroscopy (FT-IR) and space-borne AIRS/Aqua. To understand the impact of the Asian dust, a Line-by-Line radiative transfer model runs to calculate the high resolution infrared spectrum over the wave number range of $500-500cm^{-1}$. Furthermore, the radiosonde, a $PM_{10}$ Sampler, a Micro Pulse Lidar (MPL), and an Aerodynamic Particle Sizer (APS) are used to understand the vertical profile of temperature and humidity and the properties of Asian dust like concentration, altitude of dust layer, and size distribution. In this study, we found the Asian dust distributed from surface up to 3-4 km and volume concentration is increased at the size range between 2 and $8{\mu}m$ The observed dust spectrums are larger than the calculated clear sky spectrums by 15~60K for downward and lower by around 2~6K for upward in the wave number range of $800-1200cm^{-1}$. For the characteristics of the spectrum during the Asian dust, the downward spectrum is revealed a positive slope for $800-1000cm^{-1}$ region and negative slope over $1100-1200cm^{-1}$ region. In the upward spectrum, slopes are opposed to the downward one. It is inferred that the difference between measured and calculated spectrum is mostly due to the contribution of emission and/or absorption of the dust particles by the aerosol amount, size distribution, altitude, and composition.

일기속담에 대한 중.고등학생들의 인식과 과학수업에의 이용 (A Study on Secondary School Students' Recognition on Weather Proverbs and Application to Science Teaching)

  • 국동식;이철우
    • 대한지구과학교육학회지
    • /
    • 제1권1호
    • /
    • pp.85-98
    • /
    • 2008
  • Though the investigation of the suggested references proverbs related weather were collected and considered the probability of the usage on science instruction. The results are as follows. 130 proverbs related to weather were collected through the investigation of the suggested references. Most of weather proverbs are based on the states of sky, clouds, wind, precipitation, actions of animal, states of plants and the condition of people in daily life. they were classified according to weather types, natural phenomena and seasons. According to the results of analysing the students' recognition and interests on weather proverbs, most of students heard weather proverbs in their elementary school years firstly through their parents, books, and teachers. However they have only heard a few. Also many students also tend to think weather proverbs have a scientific base because weather proverbs have been told by many people through the ancient time and correspond to their personal experiences. Students responded that weather proverbs are useful for science learning on weather and can teach heritage and wisdom. After reading the suggested weather proverbs, their interests on weather proverbs were increased more than before reading. This is one of reasons why weather proverbs can be introduced to science classes. Weather proverbs were considered related to science curriculum. The third grade has a Unit "Fine days and Cloudy days", the fifth grade, "Unit of Weather Change", the Sixth grade, "Unit of Weather Forecast" , the Ninth grade, "Unit of Water cycle and Weather Change" and the tenth grade has "Unit of Earth". So the author consider that weather proverb materials can be used so effectively to bring about interest and motive in science learning.

  • PDF

맑은 날 한낮의 사면 기온분포와 일사 수광량 간 관계 (Distribution of Midday Air Temperature and the Solar Irradiance Over Sloping Surfaces under Cloudless Condition)

  • 김수옥;윤진일
    • 한국농림기상학회지
    • /
    • 제15권4호
    • /
    • pp.291-297
    • /
    • 2013
  • 소규모 집수역에서 한낮 기온의 분포와 일사수광량 간 관계를 관찰하기 위해 고도 50m급 3곳, 100m급 3곳, 300m급 3곳 등 9지점의 사면에 경사향을 달리하여 무인기상관측기를 설치하고 1년간 매일 1500 기온과 직전 4시간(1100-1500) 일사량자료를 수집하였다. 운량이 0인 맑은 날에 한정하여 각 지점의 사면 일사수광량을 계산하고 1500 기온과 비교하였다. 이때 각 지점의 경사도(slope)와 경사향(aspect)은 $30{\times}30$ m 격자를 기준으로 반경이 5, 10, 15, 20, 25, 30개 격자로 평활화 하여 사용하였다. 1500 기온에 미치는 직전 4시간 일사수광량 간에는 통계적으로 유의한 회귀관계가 인정되었으며, 반경 25개 격자(750m)로 평활화한 경우 사면 기온변이의 54%를 설명할 수 있었다(y = 0.8309x + 0.0438, $r^2$ = 0.5444).

광양만 권역의 영역 설정에 따른 입자확산 및 대기질 수치모의 비교 (Numerical Simulation and Comparison of Particle Dispersion and Air Quality with Domain Setting of Gwangyang Bay Area)

  • 이현미;이화운;이순환
    • 한국대기환경학회지
    • /
    • 제26권6호
    • /
    • pp.591-605
    • /
    • 2010
  • Recirculation of airmass in coastal region occurs because of the change from land to sea breeze and was shown to produce a contrary result on air quality. This study examines the numerical simulation to analyze the effect of recirculation flow in Gwangyang Bay, Korea. For this purpose two case studies are performed by the WRF-FLEXPART-CMAQ modeling system, each for a different Meso-Synoptic Index. Additionally this research make a comparative study of large domain (Domain L) and small domain (Domain S). The horizontal wind fields are simulated from WRF. Changes in the land-sea breeze have an effect on the particle dispersion modeling. The numerical simulation of air quality is carried out to investigate the recirculation of ozone. Ozone is transported to eastward under strong synoptic condition (Case_strong) because of westerly synoptic flow and this pattern can confirm in all domain. However ozone swept off by the land breeze and then transported to northward along sea breeze under conditions of clear sky and weak winds (Case_weak). In this case re-advected ozone isn't simulate in Domain S. The study found that recirculation of airmass must be concerned when numerical simulation of air quality is performed in coastal region, especially on a sunny day.

DETECTING VARIABILITY IN ASTRONOMICAL TIME SERIES DATA: APPLICATIONS OF CLUSTERING METHODS IN CLOUD COMPUTING ENVIRONMENTS

  • 신민수;변용익;장서원;김대원;김명진;이동욱;함재균;정용환;윤준연;곽재혁;김주현
    • 천문학회보
    • /
    • 제36권2호
    • /
    • pp.131.1-131.1
    • /
    • 2011
  • We present applications of clustering methods to detect variability in massive astronomical time series data. Focusing on variability of bright stars, we use clustering methods to separate possible variable sources from other time series data, which include intrinsically non-variable sources and data with common systematic patterns. We already finished the analysis of the Northern Sky Variability Survey data, which include about 16 million light curves, and present candidate variable sources with their association to other data at different wavelengths. We also apply our clustering method to the light curves of bright objects in the SuperWASP Data Release 1. For the analysis of the SuperWASP data, we exploit a elastically configurable Cloud computing environments that the KISTI Supercomputing Center is deploying. Two quite different configurations are incorporated in our Cloud computing test bed. One system uses the Hadoop distributed processing with its distributed file system, using distributed processing with data locality condition. Another one adopts the Condor and the Lustre network file system. We present test results, considering performance of processing a large number of light curves, and finding clusters of variable and non-variable objects.

  • PDF

Fog Sensing over the Korean Peninsula Derived from Satellite Observation of MODIS and GOES-9

  • Yoo, Jung-Moon;Jeong, Myeong-Jae;Yoo, Hye-Lim;Rhee, Ju-Eun;Hur, Young-Min;Ahn, Myoung-Hwan
    • 대한원격탐사학회지
    • /
    • 제22권5호
    • /
    • pp.373-377
    • /
    • 2006
  • Seasonal threshold values for fog detection over the ten airport areas in the Korean Peninsula have been derived, using the satellite-observed data of polar-orbit (Aqua/Terra MODIS) and geostationary (GOES-9) during two years. The values are obtained from reflectance at $0.65{\mu}m\;(R_{0.65})$ and the difference in brightness temperature between $3.7{\mu}m\;and\;11{\mu}m\;(T_{3.7-11})$. In order to examine the discrepancy between the threshold values of two kinds of satellites, the following parameters have been analyzed under the condition of daytime/nighttime and fog/clear-sky, utilizing their simultaneous observations over the Seoul Metropolitan Area. The parameters are the brightness temperature at $3.7{\mu}m\;(T_{3.7})$, the temperature at $11{\mu}m\;(T_{11}$, and $T_{3.7-11}$ for day and night. The $R_{0.65}$ data are additionally included in the daytime. The GOES-9 thresholds over the seven airport areas except the Cheongju airport have revealed the accuracy of 50% in the daytime and 70% in the nighttime, based on statistical verification for the independent samples as follows; FAR, POD and CSI. However, the accuracy decreases in the foggy cases with twilight, precipitation, short persistence, or the higher cloud above fog.

여성복 스몰사이즈 재킷 제품 생산실태- 2021년 S/S 영컨템포러리 브랜드를 중심으로 - (An analysis of the production conditions for small-sized women's jacket products - Focusing on young contemporary brands for spring/summer 2021 -)

  • 이유진;장정아
    • 복식문화연구
    • /
    • 제29권6호
    • /
    • pp.849-864
    • /
    • 2021
  • This study analyzed product conditions in terms of "size system," "clothing construction depending on fit," "details," "colors," and "prices," with an emphasis on young contemporary brands for spring/summer 2021, in order to provide basic data for the development of small-sized women's jackets. Out of 96 domestic and foreign brands, the study analyzed 254 small-sized jacket products from 23 brands that produce size-XS jackets. First, when examining the sizes for women's jackets, we found that 8 out of the 23 brands offer a size-XXS option. After conducting tree analysis to analyze the factors affecting the production of size-XXS, the study found significant results in the areas of "distinction between domestic and foreign brands" and "product price." Second, after categorizing small-sized women's jackets into 3 categories-fit-slim, basic, and straight-the study analyzed clothing construction elements depending on fit. This seasons mainly feature straight-fit's hip-line length jacket, a 4-panel pattern, and a panel without a waist dart. Third, the study, through the analysis of the colors of small-sized women's jackets, found a higher frequency of colors in the order of black (23.0%), white (13.3%), and beige tones (10.1%), with additional colors such as sky blue, rose pink, and aquamarine in production, which exhibit the senses of the seasons. Price analysis revealed that small-sized jackets constituted a price range at the mid-to-low end, as in ₩50,000-100,000 (30.3%), ₩100,000-150,000 (19.3%), and ₩150,000-200,000 (11.8%).