• Asian Journal of Atmospheric Environment
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• 제4권3호
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• pp.198-210
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• 2010

Precise analysis of local winds for the prediction of atmospheric phenomena in the planetary boundary layer is extremely important. In this study, wind profiler data with fine time resolution and density in the lower troposphere were used to improve the performance of a numerical atmospheric model of a complex coastal area. Three-dimensional variational data assimilation (3DVAR) was used to assimilate profiler data. Two experiments were conducted to determine the effects of the profiler data on model results. First, we performed an observing system experiment. Second, we implemented a sensitivity test of data assimilation intervals to extend the advantages of the profiler to data assimilation. The lowest errors were observed when using both radio sonde and profiler data to interpret vertical and surface observation data. The sensitivity to the assimilation interval differed according to the synoptic conditions when the focus was on the surface results. The sensitivity to the weak synoptic effect was much larger than to the strong synoptic effect. The hourly-assimilated case showed the lowest root mean square error (RMSE, 1.62 m/s) and highest index of agreement (IOA, 0.82) under weak synoptic conditions, whereas the statistics in the 1, 3, and 6 hourly-assimilated cases were similar under strong synoptic conditions. This indicates that the profiler data better represent complex local circulation in the model with high time and vertical resolution, particularly when the synoptic effect is weak.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 1998년도 공동 심포지엄 및 추계학술발표회
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• pp.119-122
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• 1998

Chemical analysis, measurement of pumping rates of 60 production wells and depth to water tables of 57 monitoring wells were carried to protect depletion of water resources and deterioration of water quality for the commercial portable ground-water. Borehole depth of production well averages 149m(31 boreholes), casing depth is 28m(29 boreholes), production rate is 70 $m^3$/day and depth to water table of monitoring well is 23.26m, respectively. The geology of 60 wells can be divided into Daebo granite(20), Okchun metarmorphic complex(18), Precambrian granitic gneiss(15), Bulguksa granite(4), Cheju volcanics(2), Cretaceous sedimentary rock(1). Average electrical conductivity and pH are 152$\mu$S/cm, and 7.35, respectively. The contents of major cation and anion predominantly $Ca^{2+}$>N $a^{+}$>M $g^{2+}$> $K^{+}$ and HC $O_{3}$$^{－}$ >S $O_{4}$$^{2-}$>Cl￣>F￣. Water type is predominantly $Ca^{2+}$-HC $O_{3}$$^{－}$(81.7%). It's possible that water chemistry of some wells were affected not only by the geology of boreholes penetrated but by inflows of surface water or shallow ground-water. Therefore, it is strongly necessary to steadily monitor the water quality and hydrogeologic conditins of production wells.ells.ls.ells.

• 천문학논총
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• 제27권4호
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• pp.331-334
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• 2012

We investigate the role of galaxy environment in the evolution of individual galaxies through the AKARI observations of the merging galaxy cluster A2255. MIR diagnostics using N3-S11 colors are adopted to select star-forming galaxies and galaxies in transition between star-forming galaxies and quiescent galaxies. We do not find particular enhancement of star formation rates as a function of galaxy environment, reflected in cluster-centric distance and local surface density of galaxies. Instead, the locations of intermediate MIR-excess galaxies (-1.2 < N3 - S11 < 0.2) show that star-forming galaxies are transformed into passive galaxies in the substructures of A2255, where the local surface density of galaxies is relatively high.

• 한국지반공학회논문집
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• 제30권4호
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• pp.47-63
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• 2014

육상 및 항만 구조물 설계시 적용되고 있는 토압 이론(Rankine, Coulomb, 시행쐐기법, 개량시행쐐기법)을 정리하였고, 구조물 형태에 따라 가상배면(Vitural back, wall, plane)과 구조물 벽면에 작용하는 토압 특성 등을 제시하였다. 토압 특성을 검토하기 위해 육상구조물의 경우 배면토 경사에 따른 캔틸레버식 옹벽과 벽경사에 따른 중력식 옹벽, 해상구조물은 케이슨식 안벽과 블록식 안벽을 적용하였다. 여러 가지 토압이론을 적용하여 뒷굽 길이에 따른 토압, 작용각(벽면마찰각), 벽면측으로의 활동각 등을 분석한 결과 뒷굽이 긴 경우 가상배면에서의 작용토압은 Rankine 토압과 작용각은 지표경사각, 뒷굽이 짧은 경우 Coulomb 방법과 작용각은 벽마찰각으로 산정하는 것이 가장 합리적임을 알 수 있었다. 벽면측으로의 활동각은 Rankine 이론에 의한 활동각보다 큰 것으로 나타났다. 또한, 본 논문에서는 현재 적용되고 있는 여러 가지 토압 산정법 및 작용각 중에서 항만 구조물 설계시 적용할 수 있는 적정 토압 산정방법을 제안하였다. 제안방법은 뒷굽장단 결정과 이에 따른 적정 토압산정법을 결정하고 벽면 측으로의 활동각에 따른 옹벽자중 고려 방법을 설정하도록 하였다.

• 식품과학과 산업
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• 제49권4호
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• pp.40-63
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• 2016

John Glenn, America's first man to eat anything in the near-weightless environment of Earth orbit, found the task of eating fairly easy. With improved packaging came improved food quality and menus. By the time of the Apollo Program, the quality and variety of food increased even further. Apollo astronauts were the first to have hot water, which made rehydrating foods easier and improved the food's taste. Thermostabilized pouches were also introduced on Apollo. The task of eating in space got a big boost in Skylab. It also had a food freezer and refrigerator a convenience offered by no other vehicle before or since. Two different food systems will be used for future long-duration missions to other planets, one for traveling to and from the distant body and one for use on the surface of the moon or Mars. The transit food system will be similar to the space station food system with the exception that products with three-to five-year shelf lives will be needed. Thus, this part of the trip will be similar to what occurs aboard space missions now. The surface food system, be it lunar or planetary, will be quite different. It will be similar to a vegetarian diet that someone could cook on Earth. Once crew members arrive on the surface and establish living quarters, they can start growing crops. Once the crops are processed into edible ingredients, cooking will be done in the spacecraft's galley to make the food items. Disposal of used food packaging will be an issue since there will be no Progress vehicles to send off and incinerate into the Earth's atmosphere. Packaging materials will be used that have less mass but sufficient barrier properties for oxygen and water to maintain shelf life as those now in use.

• Advances in environmental research
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• 제7권3호
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• pp.177-200
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• 2018

Sixteen USEPA priority polycyclic aromatic hydrocarbons (PAHs) in the surface water from the coastal areas of Bangladesh were analyzed by GC-MS/MS. Samples were collected in winter and summer, 2015. The total concentration of PAHs (${\Sigma}PAHs$) showed a slight variation in the two seasons, which varied from 855.4 to 9653.7 ng/L in winter and 679.4 to 12639.3 ng/L in summer, respectively. The levels of ${\Sigma}PAHs$ were comparable to or relatively higher than other coastal areas around the world. The areas with recent urbanization and industrialization (Chittagong, Cox's Bazar and Sundarbans) were more contaminated with PAHs than the unindustrialized area (Meghna Estuary). Generally, 2-3-ring PAHs were the dominant compounds. Molecular ratios suggested that PAHs in the study areas could be originated from both pyrogenic and petrogenic sources. The risk assessment revealed the extremely high ecological risk of PAHs, indicating an intense attention should be paid to PAHs pollution in the coastal areas of Bangladesh.

• 한국환경과학회지
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• 제19권3호
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• pp.281-293
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• 2010

The present study explores time and spatial thermal environment for Daegu, which is a city built on a basin area, according to varying land cover conditions of the earth's surface by analyzing data derived from meteorological observation and satellite images. The study has classified land use by utilizing MODIS satellite images and analyzed land surface temperature. Also, by using data acquired from automatic weather system, the study has evaluated the effects of atmospheric heating caused by city pavements by analyzing the sensible heat flux between the city's land surface and the atmosphere. The results are as follows. 1) Classification of land use in the Daegu area shows 46.64% of urban and built-up area, 1.39% of watersides, 35.19% of forest, 11.43% of crops, and 5.37% grasslands. 2) During the weekdays throughout the year, the land surface temperature was high for Dalseogu, Bukgu, and Seogu regions where industrial complexes could be found. Comparatively, lower temperature could be observed in the woodlands. 3) While the land surface temperature displayed the effects of pushing air upwards during the weekdays in urban areas, the reverse was true for forest regions. During the night, the temperature did not exert any significant influence on air movement.

• 한국대기환경학회지
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• 제26권4호
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• pp.367-379
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• 2010

Future climate changes over the Seoul metropolitan area (SMA) were predicted by the Weather Research and Forecasting (WRF) model using future land-use data from the urban growth model (SLEUTH) and forecast fields from ECHAM5/MPI-OM1 GCM (IPCC scenario A1B). Simulations from the SLEUTH model with GIS information (slope, urban, hill-shade, etc.) derived from the water management information system (WAMIS) and the intelligent transportation systems-standard nodes link (ITS-SNL) showed that considerable increase by 17.1% in the fraction of urban areas (FUA) was found within the SMA in 2020. To identify the effects of the urban growth on the temperature and wind variations in the future, WRF simulations by considering urban growth were performed for two seasons (summer and winter) in 2020s (2018~2022) and they were compared with those in the present (2003~2007). Comparisons of model results showed that significant changes in surface temperature (2-meter) were found in an area with high urban growth. On average in model domain, positive increases of $0.31^{\circ}C$ and $0.10^{\circ}C$ were predicted during summer and winter, respectively. These were higher than contributions forced by climate changes. The changes in surface temperature, however, were very small expect for some areas. This results suggested that surface temperature in metropolitan areas like the SMA can be significantly increased only by the urban growth during several decades.

• 한국해양학회지:바다
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• 제18권1호
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• pp.32-39
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• 2013

인공위성은 넓은 지역에 대한 전 세계의 정보를 획득하는데 유용하지만, 좁은 지역에 대한 적시적소에 촬영하는 데는 한계가 있다. 이러한 단점을 극복하기 위하여 본 연구에서는 항공기 원격탐사 시스템을 구축하였다. 항공기 원격탐사시스템은 SAR센서와 열적외선 센서로 구성되어 있으며, 획득된 자료의 방사 및 기사보정을 위하여 GPS, IMU, 온도/습도계 등도 설치하였다. SAR영상은 표면 거칠기에 따라 민감하게 반응하여 밝기 값이 달라지게 되며, 해양에서는 바람에 의해 쉽게 생성 되는 표면 장력파의 진폭이 이러한 표면 거칠기를 야기한다. 따라서 정량화된 SAR의 후방산란과 해상풍 사이의 관계식을 통해 해상풍 추출이 가능하다. 한편, 열적외선 센서는 물체의 온도를 측정하는데 유용하며, 물체와 센서 사이의 대기에 의한 효과를 보정한 후 수온 추출이 이루어진다. 이 두 센서를 탑재한 항공기로 서해안 일대를 4차례 시험비행을 수행하였으며, 이로부터 획득된 SAR 및 열적외선 영상의 품질이 연안환경 모니터링 및 해양기상 자료 추출에 충분함을 보여주었다.

• KIEAE Journal
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• 제15권1호
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• pp.117-127
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• 2015

The cool surface ratio could be used as a proxy of the overall thermal environment contributing to heat islands in urban area. This research proposes a comparative evaluation framework in an objective and quantitative way for measuring cool surface ratios. Two university campuses (Kyungpook National University: KNU, South Korea and UC Davis: University of California, Davis, USA) were selected as case study sites in order to monitor cool surface condition. Google Earth combined with digital maps realistically identified the major type of cool surfaces such as cool roofs and water bodies in the study area. Cool surfaces were sparsely identified over the KNU campus while the UC Davis campus was heavily covered by cool surfaces such as cool roofs and water bodies, resulting in almost four times more first-grade cool surfaces, as compared to KNU. It is confirmed that standard remote sensing technology can offer the viable method of measuring and comparing the campus-wide cool surface condition. It is anticipated that this research output could be used as a valuable reference to initiate a nation-wide cool surface strategy since objective evidence has been provided based on area-wide measurement for the cool surface in the two university context.