• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2013.06a
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• pp.12-13
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• 2013

본 논문은 비가 오는 장면을 촬영한 동영상에서 빗줄기를 효과적으로 제거하는 기법을 제안한다. 제안하는 기법에서는 광흐름 검출 기법을 이용하여 인접한 프레임에서 현재 프레임의 픽셀에 대응하는 픽셀을 검출하고, 확률에 따라 해당 프레임의 픽셀 적용 유무를 결정한다. 빗줄기로 검출된 픽셀을 인접한 프레임의 픽셀 값으로 대체함으로써 영상 내 빗줄기를 제거한다. 컴퓨터 모의실험을 통해 제안하는 알고리즘이 동영상에서 효과적으로 빗줄기를 제거할 수 있음을 확인한다.

• IEMEK Journal of Embedded Systems and Applications
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• v.16 no.5
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• pp.225-232
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• 2021

Deraining is one of the image restoration tasks and should consider a tradeoff between local details and broad contextual information while recovering images. Current studies adopt an attention mechanism which has been actively researched in natural language processing to deal with both global and local features. This paper classifies existing deraining methods and provides comparative analysis and performance comparison by using several datasets in terms of generalization.

• Journal of Korean Society for Atmospheric Environment
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• v.34 no.5
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• pp.659-667
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• 2018

$NO_x$ and $SO_2$ are mainly generated in the combustion of fossil fuels, and they cause secondary aerosol formation and acid rain in the atmosphere. Many studies have been conducted on the wet scrubbing process which can simultaneously reduce $NO_x$ and $SO_2$ at relatively low temperature. In this study, we conducted an experimental study on wet scrubbing by using NaOH solution. Especially, this study focuses on $NO_x$ and $SO_2$ removal characteristics by varying $NO_2/NO_x$ ratio and $SO_2$ concentration.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2224-2226
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• 1999

Non-thermal plasma techniques is applied in many fields. Recently acid rain, global warming, ozone depletion, and smog are preeminent environmental problems. The cause for this environmental problems is the flue gas. Non-thermal plasma techniques has an attention for the solution of flue gas. Non-thermal plasma is used for the removal of flue gas composed of NOx, etc. This field has grown dramatically. This experiment is performed by using cylinder type reactor under the condition of room temperature and atmosphere pressure. NO gas is used instead of flue gas. Bidirectional pulse generator is used instead of the unidirectional pulse generator to increase the efficiency.

• Journal of environmental and Sanitary engineering
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• v.16 no.3
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• pp.104-110
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• 2001

NOx coming from combustion make photochemical smog and acid rain, cause chronic respiratory disease resulting in critical hazard to environment and human health. Most composition of NOx coming from combustion is NO and the remaining small amount of $NO_x$ is $NO_2$. Currently, many technologies are developed and used to control NO release. One of these technologies is control technology through use of the adsorbent. In this study, two methods were used to make the adsorbent and compared. KOH and ${\gamma}{\;}-alumina$ were mixed by using two methods. Then, the experimental conditions were as follows: the concentrations of KOH used were 1 mole, 0.5 mole, and 0.1 mole, respectively and the amount of ${\gamma}{\;}-alumina$$250^{\circ}C$. As a result, precipitation method, which is one of the production methods of the adsorbent, showed the most removal efficiency as KOH concentration as 1 mole and reaction temperature as $100^{\circ}C$ were used. This study shows 40 to 60% of micropores of ${\gamma}{\;}-alumina$ was lost by the reaction with KOH through the analysis of SEM and BET Finally, KOH is the most predominant factor to control the removal of NO rather than micropore of the adsorbent.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.1
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• pp.45-51
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• 1992

A study on acidity in fog, dew and frost was carried out. Samples were taken during May 1990-February 1991 at two sites in Chongwon, Choongbook. The acidity of dew and of fog collected from grass at site A was 4.89 and 5.46, respectively. Dew in summer showed very strong acidity. The volume of dew deposited on grass was much less than the volume of rain, but dew is effective to diffuse acid predursors and acid materials. Dew and fog can remove more effectively atmospheric acid materiasl deoposited on grass by diurnal turbulent motion rather than direct absorption of acid predursors and materials in the atmosphere. In a polluted area, acidic dew and fog can be occurred by the direct absorption and oxidation of acidic predursors in the atmosphere as well as the role of wet removal on grass surface. Acidity of frost collected on teflon surface showed little difference to acidity of dew and fog on teflon surface. This suggests a similar absorption mechanism of atmospheric precursors and materials into dew and frost in the atmosphere. Strong acidity in dew, fog and frost appeared to occur from local pollution sources of several ten kilometres. In particular, strong acidity in dew, fog, and frost together with acid rain can accelerate a damage in ecosystems. Discussion is made on scientific analyses and seasonal variations of acidity of fog, dew and frost. A mechanism on acidification of fog, dew and frost is also discussed.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.4
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• pp.377-386
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• 2010

To identify operating parameters of the up-flow filtering system, which is available to discharge filtering residue after the rain, developed for treatment of urban storm runoff, lab scale test was carried out. Removal efficiency of SS was 68.7%, 62.2%, and 58.6% at the area roading rate of 2.46m/h, 4.68m/h, and 10m/h, respectively, filtering device is desirable to operate at the lower than 4.68m/h of area roading rate to get higher level of 60% SS removal efficiency. The removal efficiency of SS was 57.1% ~ 68.7% at the raw water SS of 100mg/L ~ 600mg/L, and the SS in treated water was maintained at the constant level through the elapsed time. It is indicate that filtering device can guarantee a certain level of effluent water quality at various raw water quality. The removal efficiency of SS to the depth of filter media was 68.3%, 78.6% at the filter depth of 10 cm, 20cm respectively. The final treated water quality was showed 30.2mg/L of CODMn, 1.60mg/L of TN and 0.25mg/L of TP. The average removal efficiencies by filtering device developed in this research were recorded slightly lower levels than other research. The main reason of these results were the first, the filter depth of the media used in this test was shallow, the second, the kind of filter media in discharge port of residue. More research to kind of filter media, filter packing rate, select of media for residue discharge port should be go on to produce optimum operating condition. The result of this study would be valuable for the application of filtration device to control of urban storm water.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.1
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• pp.23-28
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• 1996

In order to investigate the chemical components of acid precipitation at Samchok City in Korea, the rainwater was collected according to 3mm rainfall from september 1994 to december 1994. pH, electric conductivity were measured and ionic components were analyzed by Ion chromatography. As the analytical results, the average value were 6.27 for pH, 53.16 S/cm for E.C., the average concentration were 393.42 eq/1 for C $l^{[-10]}$ , 18.41 eq/1 for N $O_{3}$$^{[-10]}$ , 91.44 eq/1 for S $O_{4}$$^{2-}$, 335.92 eq/1 for N $a^{+}$, 65.66 eq/1 for N $H_{4}$$^{+}$, 18.22 eq/1 for $K^{+}$, 120.49 eq/1 for $Mg^{2+}$ and 147.04 eq/1 for $Ca^{2+}$. pH value correlated negatively with rainfall amount and the component of C $l^{[-10]}$ and N $a^{+}$ were transported to urban air by the seasalt. It showed that S $O_{4}$$^{2-}$ and N $O_{3}$$^{[-10]}$ had influence on acidity of precipitation, 73% and 27%, respectively, in this area. Ion Concentration of N $O_{3}$$^{[-10]}$ was higher than S $O_{4}$$^{2-}$ in the early rain, S $O_{4}$$^{2-}$ was higher than N $O_{3}$$^{[-10]}$ in the succeeding rain by multi-regration analysis. the percentages of removal by percipitation were higher in N $O_{3}$$^{[-10]}$ than in S $O_{4}$$^{2-}$./TEX> 2-/.

• Korean Journal of Environmental Agriculture
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• v.19 no.3
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• pp.218-222
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• 2000

Wasted${\cdot}$rested mine areas give lots of effect on around-environmental changes after mining development. Leaching water at reclaimed land has been eluted from the solid components through physical, chemical, biological procedures by waters percolated through reclaimed site. The element analysis of waste tungsten ore tailing, leaching water analysis and removal of heavy metal by zeolite were performed to investigate the influent of acid rain on the released contents of H. M. The heavy metal contents in leaching water were determined to be As $1.21\;{\sim}\;1.54\;ppm$, Pb $0.11\;{\sim}\;0.15\;ppm$ and $SO_4\;^{2-}$ was $302\;{\sim}\;378ppm$. As deionized water and simulated acid rain (pH 3,4) were percolated through columns packed tungsten ore tailing, the amount of Mn, Na, Ca which were dissolved by pH4 solution was higher than those by distilled water. However, W and Mo were eluted easily by high pH solution. The change of heavy metal concentration by column experiment packed zeolite was effective a little because heavy metals were adsorved much more by zeolite.

• Textile Coloration and Finishing
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• v.22 no.2
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• pp.94-100
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• 2010

Colored compounds adsorption from the textile dyeing effluents on activated carbons produced from various indigenous vegetable sources by zinc chloride activation is studied. The most important parameters in chemical activation were found to be the chemical ratio of $ZnCl_2$ to feed (3:1), carbonization temperature (460-470 $^{\circ}C$) and time of activation (75 min). The absorbance at 511 nm (red effluent) and 615 nm (blue effluent) are used for estimation of color. It is established that at optimum temperature ($50^{\circ}C$), time of contact (30-40 min) and adsorbent loading (2 g/L), activated carbons developed from rain tree (Samanea saman) saw dust and blackberry (Randia formosa) tree saw dust showed great capability to remove color materials from the effluents. It is observed that adsorption of reactive dyes by all types of activated carbons is more than that of disperse dyes. It is explained that because of its acidic nature the activated carbon can adsorb better reactive dye particles containing large number of nitrogen sites and $-SO_3Na$ group in their structure. The use of activated carbons from the indigenous biomass would be economical, because saw dusts are readily available waste worldwide.