• 한국환경과학회지
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• 제18권8호
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• pp.857-865
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• 2009

The physical properties of an atmospheric boundary layer in Wolryong, a west coastal region of Jeju, South Korea, in terms of the atmospheric stability and roughness length, is important and relevant to both engineers and scientists. The study is aiming to understand the atmospheric stability around this region and its effect on the roughness length. We calculate the Monin-Obukhov length(L) against 3 typical regions of the atmospheric condition - unstable regime (-5$-0.2{\leq}H/L{\leq}0.2$) and stable regime (0.2

• 전기학회논문지
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• 제57권7호
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• pp.1218-1222
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• 2008

We investigate the effect of rise time of a pulse bias voltage on atmospheric plasma generation. With the faster rise time of the pulse bias, the glow discharge appears to be more uniformly generated along the electrodes. I-V measurement confirms that higher loading power can be obtained using the faster rise time. A new understanding for atmospheric plasma generation at a micro-gap electrode is suggested.

• Journal of Astronomy and Space Sciences
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• 제9권2호
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• pp.154-164
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• 1992

The Mg II lines been extracted from the IUE archival spectra of 32 Cygni to investigate the effect of the atmospheric eclipse. The UV light curve has been reduced from the continuum flux at the center wavelength of 2807.5 ${\AA}$ in the IUE spectra. The equivalent width of the Mg II k absoption line has been measured for each spectra. The results of the light variation and flux tracing of the absorption line at the vicinity of the primary eclipse confirmed the atmospheric eclipse. The atmospheric effect lasted until the phase 0.06 in the absorptin line tracing, while it lasted until the phase 0.02 in the UV light curve, respectively.

• 대기
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• 제18권1호
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• pp.71-81
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• 2008

In this study, in order to estimate high resolution precipitation with monthly time scales, Parameter-elevation Regressions on Independent Slopes Model (PRISM) was modified and configured for Korean precipitation based on elevation, distance, topographic facet, and coastal proximity. Applying this statistical downscaling model to Korean precipitation for 5 years from 2001 to 2005, we have compiled monthly grid data with a horizontal resolution of 5-km and evaluated the model using bias, root mean square error (RMSE), and correlation coefficient between the observed and the estimated. Results show that bias, RMSE, and correlation coefficient of the estimated value have a range from 0.2% to 1.0%, 19.6% (June) to 43.9% (January), and 0.73 to 0.84, respectively, indicating that the modified Korean PRISM (K-PRISM) is reasonably worked by weighting factors, i.e., topographic effect and rain shadow effect.

• 한국동물학회:학술대회논문집
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• 한국동물학회 2001년도 한국생물과학협회 학술발표대회
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• pp.174.4-175
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• 2001

No Abstract, See Full Text

• 한국표면공학회지
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• 제42권5호
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• pp.208-215
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• 2009

We employed atmospheric plasma to reactively remove the lubricant sprayed onto such industrial electronic parts as LCD chassis during sheet-metal forming processes and investigated basically the effect of plasma parameters on cleansing the surfaces of zinc-electroplated steel plates (EGI). Specimen prepared with some controlled amount of lubricant sprayed on their surfaces beforehand were subjected to two different kinds of atmospheric plasma, one being generated by using air and the other generated by using nitrogen (99.9% purity). Locating the plasma beams at the height range between 3.5 and 13.5 mm from the surface of each specimen and radiating for 5 to 30 seconds resulted out that the cases with a position of 3.5 mm and a duration of 5 seconds or longer showed the surfaces completely cleansed without a trace of lubricant. Furthermore we found out that the plasma generated by using simple air depicted higher cleansing ability than the other one generated by using expensive nitrogen, interestingly useful very much for industrial purposes. On another aspect, we confirmed that the drilled or cut surfaces of Zn-plated steel substrate would not be oxidized even under the influence of plasma during its cleansing process. Therefore, we could probably conclude from this fore-survey that a dry process adopting atmospheric plasma for cleansing industrial parts might be determined to become successful in terms of commercialization, cautiously.

• 한국대기환경학회지
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• 제8권2호
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• pp.121-127
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• 1992

This study was carried out to investigate the features of air pollutants in rainwater and trace their transported trajectories from other countries. Chemical analysis data of rainwater and suspended particulates collected at Seoul, Kanghwa, and Taean for three years were used to evaluate the effects of long-range transport of air pollutants. Scavenging theory on washout and rainout effect during a rainy period was applied to estimate whether pollutants in the precipitation were long-range transported or not. On the other hand, precipitation weighted surface wind were evaluated to analyze the effect from local sources on atmospheric concentrations. As a result, contribution of air pollutants caused by anthropogenic sources in the precipitation which was identified to be long range transported was confirmed significantly high and trajectory of these pollutants was to be equivalent to 850mb isobar. Although concentration of acidifying components increased in the precipitation, neutralization by alkaline soil components such as $Ca^{2+}$ and $Mg^{2+}$ was conspicuous especially during Yellow-sand period.

• 한국환경과학회지
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• 제17권6호
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• pp.623-631
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• 2008

Many recent studies have concentrated upon the radiative effects of atmospheric aerosols. Though their scattering and absorption of radiation, aerosols can also induce some other important environment effects. In this study, new radiation code and aerosol data within Atmosphere General Circulation Model (AGCM) is used to assess the aerosol radiative forcing and to analyze relative climate effects. The new Kangnung National University AGCM Stratospheric-15 (KNU AGCM ST15) was integrated by using two sets of radiative effect of aerosols: CTRL as not a radiative effect of aerosols and AERO as a radiative effect of aerosols. Two cases show the difference of net shortwave radiation budget at top-of-atmosphere (TOA) is found to be about $-3.4Wm^{-2}$, at the surface (SFC) is about $-5.6Wm^{-2}$. Consequently the mean atmospheric absorption due to aerosol layer in global is about $2.2Wm^{-2}$. This result confirms the existence of a negative forcing due to the direct effect of aerosols at the surface and TOA in global annual mean. In addition, it is found that cooling over at the surface air temperature due to radiative effect of aerosols is about $0.17^{\circ}C$. It is estimated that radiative forcing of the net upward longwave radiation taken as the indirect effect of aerosol is much smaller than that of the direct effect as there is about $0.2Wm^{-2}$ of positive forcing both at TOA and at SFC. From this study, It made an accurate estimation of considering effect of aerosols that is negative effect. This may slow the rate of projected global warming during the $21^{st}$ century.

• 한국대기환경학회지
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• 제7권2호
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• pp.105-113
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• 1991

An investigation is carried out for the role of topography in governign the mesoscale distribution of $SO_2$ concentration in Seoul. The three dimensional wind fields computed for a given synoptic meteorological condition by an atmospheric mesoscale model in the terrain following coordinate have been employed to compute the three dimensional mesoscale distributions of $SO_2$ concentration by the diffusion model in Seoul area. Terrain may affect the mesoscale distributions of $SO_2$ concentration through its influence on the mesoscale wind fields. This study discusses only the terrain effect on the concentration through its modification of the wind. This effect is to produce higher concentration in lower area according to the structure of divergence fields derived from and atmospheric mesoscale model.

• 한국대기환경학회지
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• 제20권3호
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• pp.303-315
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• 2004

The change of land use such as the construction of way in mountainous area and tunnel leads to the quantitative change of the greenhouse gas. This study tried to clarify the effect of the change of land use around Miryang Ice Valley on thermal environment of micro-meteorological scale by numerical experiment. We carried out several numerical experiment under different atmospheric conditions with different amount of greenhouse gases. Heating rate increased by the greenhouse gas in the ground level is average of 0.0073 K/day. And the increasing rate if smaller than the daily average heat crossing quantity.