• Title/Summary/Keyword: GDAS

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Comparison of Model Results for Variation and Resolution of Meteorological Field Using HY-SPLIT (기상장의 종류와 해상도에 따른 HY-SPLIT 모델의 결과 비교)

  • Lee, Chong-Bum;Park, Sang-Jin;Kim, Jea-Chul;Jang, Yun-Jung
    • Journal of Environmental Impact Assessment
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    • v.19 no.3
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    • pp.223-230
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    • 2010
  • Trajectory dispersion models are used for the dispersion calculations in air quality assessments, Yellow-sand modeling, environmental planning and the emergency response. Meso-scale forcing and coastal circulations are calculated by trajectory model in the East Asia region. In this study the meteorological fields (GDAS and MM5) coupled to the trajectory model (HY-SPLIT) are applied to simulate the transport and the dispersion. Seoul is selected as a starting point of the HY-SPLIT. The sensitivity studies are performed by conducting an ensemble of simulations using the GDAS and the MM5 model for the same dispersion cases. The results in this study show a significant difference depending on the resolution of meteorological models. Additionally, in most cases of the compared tionally,results from MM5 and GDAS, the absolute and relative distance, shows significant difference and the difference increased with the increasing distance of HY-SPLIT. Therefore, for the case of small domai for twi d field distefbution over complex terrai, should be used only high model temporal or spatial resolution to improve the HY-SPLIT model results.

GDAS and UNSPSC for the Distribution Industry (유통산업에 적용되는 GDAS와 UNSPSC 분류체계)

  • 이창수
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2001.10a
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    • pp.265-268
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    • 2001
  • As growing the electronic commerce there are significant changes in the products/services catalog into the on-line environment. Advertent of e-catalog business opportunity for their own product/services enlarges the market volume and there are diverse methods for the presentation of its product/services. A method for the presentation of product/services features one uses identification and classification system. This study constructs a classification system and database layout for the product/services classification system as a part of e-catalog system. We consider the specific method for the GDAS-based dataset and UNSPSC classification system in the distribution industry.

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Calculation of Soil Moisture and Evapotranspiration for KLDAS(Korea Land Data Assimilation System) using Hydrometeorological Data Set (수문기상 데이터 세트를 이용한 KLDAS(Korea Land Data Assimilation System)의 토양수분·증발산량 산출)

  • PARK, Gwang-Ha;LEE, Kyung-Tae;KYE, Chang-Woo;YU, Wan-Sik;HWANG, Eui-Ho;KANG, Do-Hyuk
    • Journal of the Korean Association of Geographic Information Studies
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    • v.24 no.4
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    • pp.65-81
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    • 2021
  • In this study, soil moisture and evapotranspiration were calculated throughout South Korea using the Korea Land Data Assimilation System(KLDAS) of the Korea-Land Surface Information System(K-LIS) built on the basis of the Land Information System (LIS). The hydrometeorological data sets used to drive K-LIS and build KLDAS are MERRA-2(Modern-Era Retrospective analysis for Research and Applications, version 2) GDAS(Global Data Assimilation System) and ASOS(Automated Synoptic Observing System) data. Since ASOS is a point-based observation, it was converted into grid data with a spatial resolution of 0.125° for the application of KLDAS(ASOS-S, ASOS-Spatial). After comparing the hydrometeorological data sets applied to KLDAS against the ground-based observation, the mean of R2 ASOS-S, MERRA-2, and GDAS were analyzed as temperature(0.994, 0.967, 0.975), pressure(0.995, 0.940, 0.942), humidity (0.993, 0.895, 0.915), and rainfall(0.897, 0.682, 0.695), respectively. For the hydrologic output comparisons, the mean of R2 was ASOS-S(0.493), MERRA-2(0.56) and GDAS (0.488) in soil moisture, and the mean of R2 was analyzed as ASOS-S(0.473), MERRA-2(0.43) and GDAS(0.615) in evapotranspiration. MERRA-2 and GDAS are quality-controlled data sets using multiple satellite and ground observation data, whereas ASOS-S is grid data using observation data from 103 points. Therefore, it is concluded that the accuracy is lowered due to the error from the distance difference between the observation data. If the more ASOS observation are secured and applied in the future, the less error due to the gridding will be expected with the increased accuracy.

Improving Breakdown Voltage Characteristics of GDAs using Trigger Voltage

  • Lee, Sei-Hyun
    • Journal of Electrical Engineering and Technology
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    • v.5 no.4
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    • pp.646-652
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    • 2010
  • This paper investigates a method to improve the breakdown voltage characteristics of a gas discharge arrester (GDA) for a surge suppressor. The middle electrode is inserted between two terminal electrodes. Voltage application to the electrode synchronized and amplified by the impulse voltage decreases spark overvoltage from 45% to 57.6%. The decrease is caused by higher voltage slope, as opposed to applied impulse voltage (by 5.5 to 6.2 times). In addition, the GDA model using ATP-Draw was used to analyze the operation characteristics of GDAs. The test and simulation results agree to within 2% when the trigger source was used.

Development of System Model for Integrated Information Management of Construction Material (건설자재 통합정보 관리를 위한 시스템 모델 구현)

  • Han, Choong-Han;Ju, Ki-Bum
    • The KIPS Transactions:PartD
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    • v.16D no.3
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    • pp.433-440
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    • 2009
  • As information technology of constructional area develops recently, web-based on-line system is rapidly increasing to provide information on diverse constructional materials so as to enhance productivity of constructional business and to reduce cost. Since the constructional materials information provided by these systems, i.e., quality, specification, etc are not standardized, however, the staffs on the constructional site suffer considerable difficulties in using materials information when acquiring information on specific materials, e.g., using diverse information systems or repeating similar jobs. Thus, this research typified information items of constructional materials on the basis of GDAS and designed multi system model to control integrated information on constructional materials. This system can efficiently control and utilize materials information by supporting automatic classification of constructional materials to which OmniClass Part-22 and UNSPSC are applied, conditional complex retrieval of materials information, real-time automatic embodiment of electronic catalog and retrieving/controlling RFID.

COMBINED ACTIVE AND PASSIVE REMOTE SENSING OF HURRICANE OCEAN WINDS

  • Yueh, Simon H.
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.142-145
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    • 2006
  • The synergism of active and passive microwave techniques for hurricane ocean wind remote sensing is explored. We performed the analysis of Windsat data for Atlantic hurricanes in 2003-2005. The polarimetric third Stokes parameter observations from the Windsat 10, 18 and 37 GHz channels were collocated with the ocean surface winds from the Holland wind model, the NOAA HWind wind vectors and the Global Data Assimilation System (GDAS) operated by the National Center for Environmental Prediction (NCEP). The collocated data were binned as a function of wind speed and wind direction, and were expanded by sinusoidal series of the relative azimuth angles between wind and observation directions. The coefficients of the sinusoidal series, corrected for atmospheric attenuation, have been used to develop an empirical geophysical model function (GMF). The Windsat GMF for extreme high wind compares very well with the aircraft radiometer and radar measurements.

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A Survey on Women's Preference of Food Color (식품색에 대한 여성의 기호조사 II)

  • 황춘선
    • Journal of the Korean Home Economics Association
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    • v.32 no.1
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    • pp.133-150
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    • 1994
  • This study was a survey of the taste for color arrangement and the relation to taste with food color. The term of investigation and object was the same as before mentions. The data-treatment was determinded by frequence percentage chi-square and F-test as measured by SAS program for PC and statistical figures were obtained by GDAS. The results were as follows;1. In the taste of arrangement for food, color. The most frequent colors were green and white followed by a yellowish green red. In preference 50's object was difference from another aged. It's significance was showed orange yellow pink and white. 2. In the relation of food color and taste term the color shown a pungent sweet hot and delicious taste was red and a sour astringent sweet taste was orange and anastringent bitter delicate hard taste was brown and a proteiny sofe sweet delicate taste was yellow and a cool taste was yellow and a cool taste was green, and a cool, bitter taste was blue and an astrngent taste was pink, and a bitter hard, tasteeless taste was black and a proteiny sofe taste was white. But in the case of any a bitter taste it's significance was shown.

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A Study of efficient commodities Management that use it′s Contents (상품Contents를 이용한 효율적인 물품관리에 관한 연구)

  • 안종환
    • Proceedings of the CALSEC Conference
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    • 2003.09a
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    • pp.178-183
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    • 2003
  • Past commodities management concept that mean simple Management after goods purchase. Today, it developed to system that manages from purchasing plan to discard by Computer's development. But, kind of goods is very various from System Commodities to Spare Parts. Also, among use of goods, according to state, accounting operation should be associated but it is functionless real condition that can confirm uniformity goods availability actually. In this study, studied about plan that use Commodities Contents from purchase of goods to discard so that can do goods and accountant management.

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A Numerical Simulation Study on the Sensitivity of WRF Model in the Wind Field to the Steepness of Mountain Slopes (산 경사면의 기울기 변화에 따른 바람장의 민감도에 관한 WRF 수치모의 연구)

  • Han, Seon-Ho;Lee, Jae Gyoo
    • Atmosphere
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    • v.17 no.4
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    • pp.349-364
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    • 2007
  • The main purpose of this study is to examine the sensitivity of the WRF (Weather Research and Forecasting) in the wind field to the steepness of mountains in the case with a strong downslope wind occurred in the Yeongdong province. We conducted WRF simulations for February 13 2006. The initial and boundary data are from the NCEP/NCAR $1^{\circ}{\times}1^{\circ}$ GDAS. Arbitrary terrains of the mountains with a symmetric orography and an asymmetric one with steeper leeward slope, were introduced to examine the sensitivity of the shape of the mountains. The simulation with an asymmetric terrain results in stronger maximum surface wind by about $10ms^{-1}$ than with a symmetric terrain, especially in the narrow region from the peak to ~ 4 km away in the downstream. However, the maximum surface wind speed is weaker by $20ms^{-1}$ than with a symmetric terrain away from the narrow peak region. This indicates that the steeper slope leads to the intensification of downslope wind in the narrower region leeward. In addition, for the simulation with an asymmetric terrain, the strength of wave breaking is greater and the Lee wave is more dominant than for that with a symmetric terrain.