• Journal of the Korean Society of Marine Environment & Safety
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• v.16 no.4
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• pp.339-344
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• 2010

Oxygen depleted water mass can damage aquatic animals not only in direct way but also in indirect way by generating toxic substances including occurrence of hydrogen sulfide and ammonia which are also highly detrimental to animal life in the water mass. An oxygen dissolution device was developed, which makes turnover of the oxygen rich (over 20 mg/L) surface water down to the bottom where hypoxia is evident and tested the device in terms of oxygen recovery in the oxygen depleted bottom water. the device with turnover rates of $3.6\;m^2$/min at the liquid oxygen injection rate of 48~26.3 L/min could recover dissolved oxygen level to 7~25 mg/L at depth 7 m to lead to the dissolution level of over 90% by the supply of liquid oxygen. The running advantage of the device is that it does not require any auxiliary tank and higher energy for operation. Therefore, it can be highly useful device to relieve damages to the farmed animals in the oxygen depleted waters.

• Journal of the Korean earth science society
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• v.34 no.6
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• pp.479-491
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• 2013

Products of the eruption of Mt. Baekdusan are identified as volcanic materials at the estuaries of the Songhuagang river to north, the Dumangang river to east and the Amnokgang river to west. More speficially, pyroclastic flows, lahars and volcanic floods can affect an area of 400km in radius, centering around Lake Cheonji caldera. However, unlike the millenium eruption, the flow situation has been changed. Because multi-purpose dams and reserviors with a combined pondage of mora than 2 billion tons of water have been built in the rivers of which sources are originated from Lake Cheonji caldera. In addition, the flow of fluids expected to take place when the volcano has erupted is thought to be affected by artificial constructions in both direct and indirect ways. This study calculates the direction of fluids flow by using numerical analyses of pyroclastic flows, lahars and volcanic floods that can occur when the volcano of Mt. Baekdusan has erupted. We also estimate the scope of damages by pyroclastic flows, lahars, volcanic flooding caused by the pondage of the dams and water storages in and around Mt. Baekdusan. Pyroclastic flows transported over the steep slopes at the early times of eruptions move over the mountain slopes, affecting airplanes, and lahars due to leaks of Lake Cheonji could reach as far as major rivers and streams near Mt. Baekdusan. Unlike historical accounts, volcanic flood is expected to be limited in its scope of influence to reservoirs bigger than Lake Cheonji in pondage.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.4
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• pp.354-361
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• 2016

While the amounts of oil spill caused by the VLCC Hebei Spirit indicated 2.5 times more than that of the VLCC Sea Prince, the economic, environmental, and social damages derived from the Hebei Spirit spill were estimated to be about 30 times greater than those from the Sea Prince incident. This study consolidates the appropriate justification for building a multi-purpose large oil spill response vessel to allow swift and efficient handling of catastrophic marine pollution events through an analysis of technical and economic feasibility of such a project. The result of the technical feasibility analysis illustrates that a hopper dredge and oil spill response vessel with a capacity of 4,000 tons should be more appropriate. The result of the economic feasibility analysis indicates that under the most conservative estimates the project appears to be slightly impractical, with a benefit/cost ratio of 0.82, in which self-help efforts, however, can facilitate the project. And medium to optimistic estimates present benefit/cost ratios are estimated to be 2.72 and 5.82 respectively, representing apparent economic feasibility.

• Journal of Conservation Science
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• v.31 no.4
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• pp.403-409
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• 2015

Malachite and Azurite are the typical copper system pigments which used the mural paintings since ancient times. The mural painting is at risk for damages of the painting layer by atmosphere gas because it is exposed at external environment. In this study, it did experiment about an effect to Malachite and Azurite by environmental pollution gas($NO_2$, $CO_2$, $SO_2$) then analysis and estimate about test for pieces using mural painting colored that two pigments. As a result, Malachite and Azurite were changed on $NO_2$ but not changed $CO_2$ and $SO_2$. Especially as the concentration of $NO_2$ is increased, exfoliation of the pigment layer weave remarkably formed pores on the pigment particles on SEM, the phenomenon to be pieces were observed together with smaller particles. In the case of Malachite that were exposed to $NO_2$ gas, new compounds(Rouaite : dicopper (nitrate(V) trihydroxide, $Cu_2(NO_3)(OH)_3$)) was appeared by XRD analysis. Therefore, there had been able to verify the fact that the cause exfoliation and discoloration phenomena accompanied by chemical changes for Malachite and Azurite.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.1D
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• pp.51-63
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• 2011

This study suggests that prior to construction of the 2nd Changwon tunnel and implementation of the demanded free of charge on Changwon tunnel, it is recommended to improve the traffic facilities and management of the traffic condition in order to create an efficient road that will keep traffic flow to a minimum and maintain the facilities proper working order. It has been generally accepted that the 2nd Changwon tunnel is necessary to construct and open as soon as possible. This is due to the service level of current traffic volume in the Changwon tunnel pay toll road which have been so congested that the fees have increased causing a public complaint to be filed, demanding a early free of charge be implemented for the Changwon tunnel. Furthermore, the objective and impartial analysis of the traffic situation based on a simulation of the alternative and traffic congestion fees has been provided to make the early free of charge on toll road as soon as possible. Finally, careful attention should be paid to seek to make the early free of charge on toll road in order to minimize the damages both specified and unspecified that may arise the prompt settlement of construction repayments and security of minimum management fees should be given priority over other alternatives.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.1
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• pp.19-27
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• 2017

This research was aimed to analyze landslide susceptibility and compare the prediction accuracy using ensemble frequency ratio (FR) and logistic regression at the Inje area, Korea. The landslide locations were identified with the before and after aerial photographs of landslide occurrence that were randomly selected for training (70%) and validation (30%). The total twelve landslide-related factors were elevation, slope, aspect, distance to drainage, topographic wetness index, stream power index, soil texture, soil sickness, timber age, timber diameter, timber density, and timber type. The spatial relationship between landslide occurrence and landslide-related factors was analyzed using FR and ensemble model. The produced LSI maps were validated and compared using relative operating characteristics (ROC) curve. The prediction accuracy of produced ensemble LSI map was about 2% higher than FR LSI map. The LSI map produced in this research could be used to establish land use planning and mitigate the damages caused by disaster.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1479-1487
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• 2013

The river levee collapse and flood damages are dramatically increased due to the floods which caused by abnormal weather nowadays. The counterplan like TDR(Time Domain Reflectometry) river levee leaking exploration technique is needed to that levee failure causes of levee failure such as levee failure by penetration, piping, inadequate levee materials selection, poor compaction are almost 52% of the failure. This research practiced various comparing experiments of existing TDR(probe and tube types) and developing CAP type TDR to evaluate acrylic small CAP mould and low-cost TDR levee leaking monitoring system which was used probe type TDR. As the result, evaluated TDR system had 20cm critical exploration performance which was a leaking exploration performance, The functional ratio of TDR exploration sensitivity of dry density was sensitive more than 3 times than dry density, and weathered granite soil foundation water contents(w)-dielectric constant(${\epsilon}$) corelation formula was suggested to measure functional ratio on developing cap type TDR system.

• Journal of Life Science
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• v.27 no.3
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• pp.310-317
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• 2017

Mammalian cells control cellular homeostasis using a variety of defensive enzymes in order to combat against environmental oxidants and electrophiles. NF-E2-related factor-2 (NRF2) is a transcription factor that, in response to an exposure to oxidative stress, translocates into the nucleus and modulates the inducible expression of various phase II cytoprotective enzymes by binding to the antioxidant response element (ARE). In the present study, we have acquired 400 ethanol extracts of traditional medicinal plants and attempted to find out possible extract(s) that can increase the NRF2/ARE-dependent gene expression in human keratinocytes. As a result, we have identified that ethanol extracts of Rheum undulatum and Inula japonica strongly activated the ARE-dependent luciferase activity in HaCaT- ARE-luciferase cells. Exposure of ethanol extracts of Rheum undulatum and Inula japonica increased the viability and activated transcription and translation of NRF2-dependent phase II cytoprotective enzymes in HaCaT cells, such as heme oxygenase-1 (HO-1) and NAD[P]H:quinone oxidorecutase-1 (NQO1). In addition, ethanol extracts of Rheum undulatum and Inula japonica suppressed 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced generation of intracellular reactive oxygen species (ROS), thereby inhibiting the formation of 8-hydroxyguanosine (8-OHG) and 4-hydroxynonenal (4-HNE) in HaCaT cells. Together, our results demonstrate that ethanol extracts of Rheum undulatum and Inula japonica exert anti-oxidant effects via the induction of NRF2/ARE-dependent gene expression in human keratinocytes.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.3
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• pp.267-274
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• 2017

Recently, several researches have been studied on agricultural automation system according to convergence of IT technology with agriculture. An automatic control system of the growth environment in crops is one of the these researches. The controls of damages caused by diseases and insects pest in crops are mainly carried out by manual mode or semi-automatic mode because of farmer's concerns for poor efficiency. But, this situation needs to be improved because it occurs various problems, such as human exposure to toxic pesticides, environmental pollution and waste due to drug overuse. In order to solve these problems, we developed an automatic quantity control system which based on the amount of pesticides for area under cultivation. The amount of pesticides is calculated according to the manufacturer's instruction for pesticides. To verify the effectiveness of our developed automatic system, we also compared with the systems of manual mode and the semi-automatic mode. The experimental results of a pest control performance of an automatic quantity control system showed that automatic system can reduce overuse of drugs. These results suggested that it can be expected to replace the existing system, with equivalent effectiveness to the manual mode.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.263-272
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• 2012

The potential as natural herbicide of d-limonene natural agent was conducted on several weeds in a greenhouse and Sciyos angulatus in field condition. Herbicidal activity of foliar application at a concentration of 100 and 200 kg ai $ha^{-1}$ of d-limonene on seven weed species was completely killed in a greenhouse condition. Also, d-limonene at a concentration of 50 kg ai $ha^{-1}$ was completely killing on Abutilon theophrasti, Aeschynomene indica, Echinochloa crus-galli and Digitaria ciliaris 3 days after treatment. While pre-emergence treatment of d-limonene concentration of 12.5 to 200 kg ai $ha^{-1}$ showed not significant visible damages. Phytotoxic symptoms of d-limonene by foliar treatment were characterized by wilting and burn-down of leaves and stems followed by discoloration, finally, plant death. Crop selectivity at d-limonene concentration of 100 kg ai $ha^{-1}$ over to five main crops including Zea mays by foliar application was not at all. Field trial of foliar treatment with d-limonene 70 to 140 kg ai $ha^{-1}$ have effectively controled over 5~20 leaf stages of S. angulatus at the natural habitats. And herbicidal efficacy of foliar application on S. angulatus with carrier volume in field condition was increased with dose dependent manners. These results suggest that d-limonene is considered possible as herbicide, and may be further optimized for natural agent for environmental friendly natural herbicide.