• Economic and Environmental Geology
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• v.36 no.6
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• pp.501-510
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• 2003

Several geophysical surveys(electrical resistivity, electromagnetic, seismic refraction, CPR) were conducted to primarily investigate the gallery and the geomembrane at an abandoned mine(Imcheon mine). The subsurface structure mapped from seismic refraction survey mainly consists of three velocity layers(>1000 m/s, 1000∼2000 m/s,＜2000 m/s). Top of the bedrock, whose velocities exceed 2000 m/s, appears to be at depth of 7.5∼10m. Higher resistivities (of ten thousands-hundred of thousands ohm-m) are interpreted to be associated with a open(cavities) gallery. The events at depth of approximately 0.5∼0.7m in GPR sections are probably caused by high-density-poly-ethylene geomembrane. Taking into consideration of the differences in the spatial resolution between georadar and electrical surveys, the events of geomembrane correspond to the top of the high resistivities at depth of about 2m. The segments, characterized with the higher conductivities in the electromagnetic data and the lower resistivities in the electrical resistivity data, are probably associated with surface water or tear zone of geomembrane.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.4 s.48
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• pp.485-489
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• 2004

Melanin pigmentation in human skin is a major defensive mechanism against ultraviolet light of the sun. Tyrosinase plays a key role in the biosynthesis of melanin. This is why many researches have been focused on regulations in controlling the epidermal melanization. We found that extract of Canavalia lineata inhibits mushroom tyrosinase activity, dopa oxidase activity, and melanin synthesis in B16F10 melanoma cells. To elucidate mRNA level reverse transcription polymerase chain reaction (RT-PCR) technique was used. It was revealed that A subfraction of $CHCI_3$ extract of Canavalia lineara reduced the tyrosinase mRNA expression of B16F10 melanoma cells by reverse transcription polymerase chain reaction (RT-PCR) technique.

• Journal of KIISE:Information Networking
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• v.27 no.3
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• pp.288-300
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• 2000

본 논문에서는 효율성, 안전성 및 이중사용방지 요구 조건을 만족하면서 동시에 시스템 사용과정에서 생길 수 있는 여러 분쟁 유형에 대해서 효과적으로 대처할 수 있는 초소액 지불시스템을 제안한다. 이를 위하여 기존의 시스템들이 효율성 향상을 위해 많이 사용해 온 S/KEY 방식의 해쉬 체인을 변형한 이중 해쉬체인 구조를 제안한다. 제안 시스템인 mPay-1, mPay-2는 이 구조를 기반으로 하였으며 안전성 및 분쟁해결성 측면에서 좋은 결과를 보인다. mPay-1은 기존의 시스템과 동일한 효율성을 갖으나 보다 안전하다. mPay-1의 확장형인 mPay-2는 추가적으로 여러 분쟁 유형들에 대해 효과적으로 대처할 수 있다.

• Journal of the Korea Society for Simulation
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• v.30 no.2
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• pp.23-31
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• 2021

Defense M&S(Modeling & Simulation) requires weapon effectiveness index which indicates Ph(Probability of hit) and Pk(Probability of kill) values on various impact and environmental conditions. The index is usually produced by JMEM(Joint Munition Effectiveness Manual) development process, which calculates Pk based on the impact condition and circular error probable. This approach requires experts to manually adjust the index to consider the environmental factors such as terrain, atmosphere, and obstacles. To reduce expert's involvement, this paper proposes a meta-model based method to produce weapon effectiveness index. The method considers the effects of environmental factors during calculating a munition's trajectory by utilizing high-resolution weapon system models. Based on the result of Monte-Carlo simulation, logistic regression model and Gaussian Process Regression(GPR) model is respectively developed to predict Ph and Pk values of unobserved conditions. The suggested method will help M&S users to produce weapon effectiveness index more efficiently.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.13 no.2
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• pp.291-298
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• 1995

This paper describes the test results of terrain corrections as the short wave length effect and geoid effects in gravity field modelling using Digital Terrain Model(DTM) in Korea. For a rigorous determination of terrain correction a dense grided DTM data wave prepard spacing $500\times{500m}$ was used for the computation of terrain effects. From the results obtained by the mass prism model and the mass line model, we were found that the terrain effects are large depend on the topography in the test area. It means that we should considered the terrain effects for the precise geoid determination.

• Journal of Korean Society of Forest Science
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• v.85 no.1
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• pp.96-106
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• 1996

Red alder(Alnus rubra Bong.) seedlings inoculated with Frankia only or both Frankia and spores of Alpova diplophloeus(Zeller & Dodge) Trappe & Smith were grown in a greenhouse for ten weeks. The ten-week-old seedlings were fertilized with six nitrogen(N) and phosphorus(P) fertility regimes (no fertilization, 10mM $NH_4NO_3$, 50mM $NH_4NO_3$, 5mM $KH_2PO_4$, 10mM $NH_4NO_3+5mM$ $KH_2PO_4$, and 50mM $NH_4NO_3+5mM$ $KH_2PO_4$) three times a week for ten weeks. The higher N-fertilization significantly increased mycorrhiza formation by greenhouse contaminant mycorrhizal fungi, but decreased N-fixation and P concentration in nodule tissues. P-fertilization significantly increased nodule and shoot dry weight, and P concentration in plant tissues. When N was highly fertilized, however, the P-fertilization effect disappeared in nodule P concentration but doubled in leaf P concentration. A. diplophloeus inoculation significantly increased diameter growth and $CO_2$ exchange rate, but decreased leaf dry weight. Our results suggest that the higher N- or P-fertilization affect nitrogenase activity and mycorrhizal development but the effects are changed by their interactions.

• Tunnel and Underground Space
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• v.28 no.6
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• pp.609-619
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• 2018

This study was carried out at a local limestone mine to analyze the ventilation efficiency of the shaft equipped with a main fan. The results show that its ventilation efficiency is clearly verified for the natural as well as the mechanical ventilation. The airflow rate of $11.7m^3/s$ was induced by the natural ventilation force and the maximum quantity is almost same as the airflow rate estimated by monitoring the average temperatures in the upcast and downcast air columns. Meanwhile, the airflow rate exhausted by the main fan through the shaft was $20.3{\sim}24.8m^3/s$; variation of the quantity was caused by the upward shift of the mine ventilation characteristic curve due to the frequent movement of the equipment. This indicates efforts are required to reduce the ventilation resistance and raise the quantity supplied by the main fan. The turbulent diffusion coefficients along the 1912 m long airway from the portal to the shaft bottom was estimated to be $15m^2/s$ and $18m^2/s$. Since these higher coefficients imply that contaminants will be dispersed at a faster velocity than the airflow, prompt exhaust method should be planned for the effective air quality control. The ventilation shaft and main fan are definitely what local limestone mines inevitably need for better working environment and sustainable development.

• KSBB Journal
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• v.21 no.6 s.101
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• pp.444-450
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• 2006

Skin anti-aging effect of Forsythia viridissima L. extract was evaluated by using antioxidant assay, expression of type I procollagen, and UVA-induced matrix metalloproteinase-1 in human dermal fibroblasts. Matairesinol-rich Forsythia viridissima L. extract was showed the scavenging activity of radicals and reactive oxygen species with the $IC_{50}$ values of $4.50\;{\mu}m/ml$ against 1,1-diphenyl-2-picrylhydrazly radical and $542.43\;{mu}m/ml$ against superoxide radicals in the xanthine/xanthine oxidase system, respectively. The type I procollagen was increased 33.76% by treatment with matairesinol-rich Forsythia viridissima L. extract, and UVA-induced MMP-1 was reduced 35.78% in a dose dependent manner. In the human skin irritation test, 2% matairesinol-rich Forsythia viridissima L. extract did not show any adverse effect. Also, the clinical study indicated that a cream group treated with 0.2% matairesinol-rich Forsythia viridissima L. extract significantly reduced skin wrinkles, as compared with a non-treated cream group (p < 0.05). These results suggest that Forsythia viridissima L. extract may be useful as a potential source of functional anti-aging cosmetics.

• Applied Chemistry for Engineering
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• v.16 no.3
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• pp.348-353
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• 2005

The extracts from natural and fermented products such as Artemisia plants, Rhodiola Salientness, fermented soybeans and soybean paste were used to investigate the whitening effect. 10 g of Artemisia plant were added to 300 mL of ethanol and extracted by sonification at room temperature for 3 h. The extract was further partitioned by the equal volume percent in the order of the n-hexane, chloroform and ethyl acetate. 5 g of Rhodiola salientness was also added to 150 mL of methanol and extracted at the room temperature for 12 h. The effluents from a chromatographic column ($3.9{\times}250mm$, $C_{18}$, $15{\mu}m$) were collected and concentrated in two parts. The extraction of fermented soybeans and soybean paste were done by 60% ethanol. In this work, tyrosinase inhibitory activity and melanin inhibitory effect were measured to confirm the whitening effect. The water layer of Artemisia princeps Pampan showed the good inhibitory of antioxidant, while the hexane layer of Artemisia iwayomogi Kitamura and the chloroform layer of Artemisia princeps Pampan had the excellent melanin inhibitory effect. The Rhodiola salientness had the superior whitening effect to the arbutin in in-vivo melanin production ratio assay. However, the fermented soybeans and soybean paste did not show any whitening effect.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.587-593
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• 1998

To elucidate anti-tumor promoter from seaweed, the anti-tumor promoting activity of Ecklonia stolonifera, Undaria pinnatifida and Laminaria japonica extracts were determined by Epstein-Barr virus (EBV)-early antigen (EA) induction caused by a tumor promoter, teleocidin B-4. The methanol extracts of seaweed were subsequently fractionated with diethyl ether, distilled water, chloroform and ethyl acetate. Among the solvent fractions tested, chloroform and ethyl acetate fraction of E. stolonifera showed a high anti-tumor promoting activity at the levels of 88.0 and $85.9\%$ by the addition of 20 ${\mu}g/m{\ell}$, respectively. To characterize anti-tumor promoters from solvent fractions of E. stolonifera, the effects of phenols, chlorophyll derivatives and carotenoids on the anti-tumor promoting activity were investigated. Phenols, such as bromophenol and phloroglucinol showed anti-tumor promoting activity of $57\~66\%$ at 20 ${\mu}g/m{\ell}$. Pigments, such as chlorophylls and carotenoids exerted high anti-tumor promoting activities. Chlorophyll a and pheophorbide a exhibited the activity of $77.4\%$ and $66.6\%$ at 5${\mu}M/m{\ell}$, respectively. The active compounds of carotenoids were tentatively identified as lutein and $\alpha-cryptoxanthin$ from the profiles of visible spectra and R_f value of their authentic compounds, and showed anti-tumor promoting activities of $76.9\%$ and $84.4\%$ at dose of 20 ${\mu}g/m{\ell}$, respectively.