• Title/Summary/Keyword: Sst I

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Error Analysis of Three Types of Satellite-observed Surface Skin Temperatures in the Sea Ice Region of the Northern Hemisphere (북반구 해빙 지역에서 세 종류 위성관측 표면온도에 대한 오차분석)

  • Kang, Hee-Jung;Yoo, Jung-Moon
    • Journal of the Korean earth science society
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    • v.36 no.2
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    • pp.139-157
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    • 2015
  • We investigated the relative errors of satellite-observed Surface Skin Temperature (SST) data caused by sea ice in the northern hemispheric ocean ($30-90^{\circ}N$) during April 16-24, 2003-2014 by intercomparing MODerate Resolution Imaging Spectroradiometer (MODIS) Ice Surface Temperature (IST) data with two types of Atmospheric Infrared Sounder (AIRS) SST data including one with the AIRS/Advanced Microwave Sounding Unit-A (AMSU) and the other with 'AIRS only'. The MODIS temperatures, compared to the AIRS/AMSU, were systematically up to ~1.6 K high near the sea ice boundaries but up to ~2 K low in the sea ice regions. The main reason of the difference of skin temperatures is that the MODIS algorithm used infrared channels for the sea ice detection (i.e., surface classification), while microwave channels were additionally utilized in the AIRS/AMSU. The 'AIRS only' algorithm has been developed from NASA's Goddard Space Flight Center (NASA/GSFC) to prepare for the degradation of AMSU-A by revising part of the AIRS/AMSU algorithm. The SST of 'AIRS only' compared to AIRS/AMSU showed a bias of 0.13 K with RMSE of 0.55 K over the $30-90^{\circ}N$ region. The difference between AIRS/AMSU and 'AIRS only' was larger over the sea ice boundary than in other regions because the 'AIRS only' algorithm utilized the GCM temperature product (NOAA Global Forecast System) over seasonally-varying frozen oceans instead of the AMSU microwave data. Three kinds of the skin temperatures consistently showed significant warming trends ($0.23-0.28Kyr^{-1}$) in the latitude band of $70-80^{\circ}N$. The systematic disagreement among the skin temperatures could affect the discrepancies of their trends in the same direction of either warming or cooling.

간 대사효소의 유전자 발현조절에 관한연구

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    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.192-192
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    • 1994
  • 본 논문에서는 cytochrome P450 LA1 유전자의 5'-upsteam 조절부위의 클로닝을 실시하였다. pUC19 vector에 연결시킨 3.4 Kb 크기의 Pstl DNA조각을 Sst1, Nco1 제한 효소로 자른 뒤, Exonuclease III 를 처리하여 약 200bp 씩의 차이를 갖는 여러 크기의 plasmid들을 얻었다. 이 plasmid 의 핵산서열을 알아보기 위해 dideoxy nucletide를 이용한 sequencing방법으로 그 핵산서열의 결정 실험을 시도하였다. 또한, 다환상 방향족 탄화수소 화합물에 반응성을 갖는 C57BL/6N 생쥐와 반응성을 갖지않는 DBA/2N 생쥐에 있어 phase II 대사 효소인UDP-glucuronosyltransferase 효소활성에 대한 3-methylcholanthrene의 영향을 알아보기 위해 C57BL/6N 생쥐와 DBA/2N 생쥐에 각각 다른 농도의 3-methylcholanthrene을 처리하거나 각기 다른 시간에 3-methylcholanthrene를 처리하였다. 그 결과 UDP-glucuronosyl-transferase의 mRNA가 3-methylcholanthrene양의 증가에 따라, 처치시간이 길어짐에 따라 증가되어지며 그 mRNA위 크기는 약 2.2Kb 정도임을 알았다. 이로부터 UDP-ghucuronosyltransferase 또한 cytochrome P45O와 함께 다환상 방향족 탄화수소 화합물 조절인자를 통한 조절을 받을 것이며 phase I phase II 약물 대사 효소가 조절상 밀접한 관련을 가짐을 예측할 수 있었다.

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Molecular Cloning and Expression of a Xylanase Gene from Alkalophilic Bacillus sp.

  • Yu, Ju-Hyun;Kang, Yun-Sook;Park, Young-Seo;Bai, Dong-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.1 no.4
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    • pp.251-255
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    • 1991
  • A 16 kilobase (kb) HindIII fragment of alkalophilic Bacillus sp. YC-335 containing a gene for xylanase synthesis was inserted at the HindIII site of pBR322 and cloned in Escherichia coli HB101. After subcloning of recombinant plasmid pYS52, the 1.5 kb fragment was found to code for xylanase activity, and the hybrid plasmid was named pYS55. The DNA insert of the plasmid was subjected to restriction enzyme mapping, which showed that pYS55 had single site for PuvII and SstI in the 1.5 kb insert fragment. Southern hybridization analysis revealed that the cloned gene was hybridized with chromosomal DNA from alkalophilic Bacillus sp. YC-335. About 64% of the enzyme activity was observed in the extracellular and periplasmic space of E. coli HB10l carrying pYS55.

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Thermo-Flow Analysis of Offset-Strip Fins according to Prandtl Number (Prandtl 수에 따른 옵셋 스트립 핀에서의 열 및 유동 분석)

  • Joo, Youn-Sik;Kong, Dong-Hyun;Lee, Kwan-Soo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.6
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    • pp.340-346
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    • 2009
  • This paper numerically investigates thermo-flow characteristics of offset strip fins to obtain a correlation between heat transfer and pressure drop. The flow was divided into three regimes, i.e. laminar, transition and turbulent. The predicted j and f values from the SST k-$\omega$ turbulence model agreed with previous correlations with the error less than 20% in transition and turbulent regimes. Heat transfer and pressure drop were predicted by varying Prandtl number from 0.5 to 40. The Prandtl number showed little effects on pressure drop but had great effect on the heat transfer characteristics. An overall correlation to predict j was suggested by incorporating the effect of Pr and a new j correlation was suggested for each Pr.

Correlations of Heat Transfer and Pressure Drop for Offset Strip Fins (옵셋 스트립 핀에서의 열전달 및 압력 강하 상관식)

  • Kim, Min-Soo;Lee, Kwan-Soo
    • Proceedings of the KSME Conference
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    • 2008.11b
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    • pp.2274-2279
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    • 2008
  • This paper numerically investigates thermo-flow characteristics of offset strip fins to obtain a correlation of heat transfer and pressure drop. The flow is divided into three regimes, i.e. laminar, transition and turbulent. The predicted j and f values from the SST k-w turbulence model agree with previous correlations with the error less than 20% in transition and turbulent regimes. Prandtl number is varied from 0.5 to 40 and a correlation to predict heat transfer and pressure drop for offset strip fins is suggested.

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Thermo-Flow Analysis of Offset-strip fins according to Prandtl Number (Plandtl 수에 따른 옵셋 스트립핀에서의 열 및 유동 분석)

  • Joo, Youn-Sik;Kim, Min-Soo;Lee, Kwan-Soo
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.233-238
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    • 2008
  • This paper numerically investigates thermo-flow characteristics of offset strip fins to obtain a correlation between heat transfer and pressure drop. The flow was divided into three regimes, i.e. laminar, transition and turbulent. The predicted j and f values from the SST k-$\omega$ turbulence model agreed with previous correlations with the error less than 20% in transition and turbulent regimes. Heat transfer and pressure drop were predicted by varying Prandtl number from 0.5 to 40. The Prandtl number showed little effects on pressure drop but had great effect on the heat transfer characteristics. An overall correlation to predict j was suggested by incorporating the effect of Pr and a new j correlation was suggested for each Pr.

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Flow Analysis and Performance Evaluation of a Ventilation Axial-Flow Fan Depending on the Position of Motor (환기용 축류송풍기의 유동해석 및 모터 위치에 따른 성능 특성 연구)

  • Kim, Jae-Woo;Kim, Jin-Hyuk;Kim, Kwang-Yong
    • The KSFM Journal of Fluid Machinery
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    • v.13 no.4
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    • pp.25-30
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    • 2010
  • Flow analysis and performa nce evaluation have been performed for a ventilation axial-flow fan with different positions of the motor. Two different positions of motor have been tested; one is in front of the impeller and the other is behind the impeller. Flow analyses are performed by solving three-dimensional Reynolds-averaged Navier-Stokes equations through a finite-volume solver. Preliminary numerical calculations are carried out to test the performances of different turbulence models, i.e., SST model, k-$\omega$ model, and k-$\varepsilon$ model with and without using empirical wall function in the flow analysis. The validation of numerical analyses has been performed in comparison with the experimental data. The numerical results for the performance characteristics of the ventilation axial-flow fan with two different positions of the motor have been presented.

Electrical characteristic of differential ternary chalcogenide thin films (칼코게나이드 3원계 박막에서의 전기적 특성에 관한 연구)

  • Yang, Sung-Jun;Shin, Kyung;Lee, Jae-Min;Chung, Hong-Bay
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07a
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    • pp.377-380
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    • 2004
  • The phase transition between amorphous and crystalline states in chalcogenide semiconductor films can controlled by electric pulses or pulsed laser beam; hence some chalcogenide semiconductor films can be applied to electrically write/erase nonvolatile memory devices, where the low conductive amorphous state and the high conductive crystalline state are assigned to binary states. GeSbTe(GST), AsSbTe(AST), SeSbTe(SST) used to phase change materials by appling electrical pulses. Thickness of ternary chalcogenide thin films have about 100nm. Upper and lower electrode were made of Al. It is compared with I-V characteristics after impress the variable pulses.

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Association Study between the Genetic Variations of the Apo AI-CIII-AIV Gene Cluster and Hypertension among Koreans

  • Kang, Byung-Yong;Kang, Chin-Yang;Ki, Tae-Kim;Bae, Joon-Seol;Oh, Sang-Duk;Kim, Jae-Hyun;Lee, Kang-Oh
    • Toxicological Research
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    • v.18 no.4
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    • pp.341-347
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    • 2002
  • Hypertension is a multifactorial disorder in which the genetic and environmental factors are involved. In a view of the effects for hypertension as a risk factor for hypertension, we investigated the genotype and allele frequencies in the four RFLPs of the apo AI-CIII-AIV gene cluster (G to A mutation at position -75 in the apo AI promoter SstI RFLP in the ape CIII gene and HincII and HinfI RFLPs in the apo AIV gene) in the Korean patients with hypertension and normal controls. The AA genotype frequency of the G to A promoter polymorphism in hypertensives was significantly higher than that of normotensives (P < 0.05). None of the other polymorphisms showed a difference in genotype frequency between two groups. Therefore, our result suggest that the G to A promoter polymorphism of the ape AI gene may be useful as genetic marker in the ethiology of hypertension.

Effect of a Coupled Atmosphere-ocean Data Assimilation on Meteorological Predictions in the West Coastal Region of Korea (대기-해양 결합 자료동화가 서해 연안지역의 기상예측에 미치는 영향 연구)

  • Lee, Sung-Bin;Song, Sang-Keun;Moon, Soo-Hwan
    • Journal of Environmental Science International
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    • v.31 no.7
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    • pp.617-635
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    • 2022
  • The effect of coupled data assimilation (DA) on the meteorological prediction in the west coastal region of Korea was evaluated using a coupled atmosphere-ocean model (e.g., COAWST) in the spring (March 17-26) of 2019. We performed two sets of simulation experiments: (1) with the coupled DA (i.e., COAWST_DA) and (2) without the coupled DA (i.e., COAWST_BASE). Overall, compared with the COAWST_BASE simulation, the COAWST_DA simulation showed good agreement in the spatial and temporal variations of meteorological variables (sea surface temperature, air temperature, wind speed, and relative humidity) with those of the observations. In particular, the effect of the coupled DA on wind speed was greatly improved. This might be primarily due to the prediction improvement of the sea surface temperature resulting from the coupled DA in the study area. In addition, the improvement of meteorological prediction in COAWST_DA simulation was also confirmed by the comparative analysis between SST and other meteorological variables (sea surface wind speed and pressure variation).