• International Journal of Highway Engineering
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• v.16 no.3
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• pp.59-66
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• 2014

PURPOSES : This study is to suggest heavy snow risk analysis in Seoul. METHODS : Recently, the increase of extreme weather caused by global warming raises the occurrences of unpredictable natural disasters and the loss potential of human disasters by land use facilities accumulation. It is necessary to develop the risk analysis for the natural and human disasters. RESULTS : In this study, heavy snow risk analysis among natural disasters in Seoul was suggested. The spatial unit of risk analysis level was established for the lines and administrative districts. CONCLUSIONS : The risk analysis was performed using risk matrix of disaster occurrence score and disaster damage score. The components affecting the risk disaster analysis by types were analyzed and the application of heavy snow risk analysis was suggested.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.34 no.3
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• pp.167-173
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• 2008

Pearlescent pigments have been widely used in cosmetic applications. Up to date; the most widely used pearl effect pigment is the mica-based pigment, which uses natural mica as the substrate that is in turn coated with metal of oxide interference layer. However, when natural mica is employed as a base material the final product often has a yellowish color, mainly due to the fact that natural mica contains low levels of iron as an impurity[1,2]. This study was focused on developing a pearl pigment which might have a similar sparkling effect as snow. This effect was found to be due to its structure and purity, and this concept was also applied to development of our pearl pigments. More specifically, this invented pearl effect pigments are the mixture of glass-flake and glass-flake coated metal oxides and present the optical properties of snow matrix such as refractive index and particle size, unlike only the glass-flake or glass-flake coated metal oxides to be applied in. Using base material having similar physical properties (refractive index and particle size) as snow matrix as platelet for pearl effect pigments, these invented pigments present a three-dimensional glittering effect of the snow matrix. With this invented figments an applied; we achieved the beauty of snow crystal from makeup products containing these pigments.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2006.06a
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• pp.463-484
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• 2006

본 연구는 많은 기업들이 SCM의 중요성을 인식하고 도입하여 활용을 하고 있는 정보시스템의 발전 단계에서 공급사슬에 참여하고 있는 기업이 어떻게 SCM을 활용하고 있는지에 초점을 둔 연구라 할 수 있다. 기존 연구에서 도출한 SCM 활용 목적에 대한 설문 항목을 중심으로 기업이 활용하고 있는 SCM 활용 패턴을 도출하였다. 군집 분석 방법을 활용하여 집단에 특성을 배정하여 동일 집단에 속한 대상의 유사성을 갖게 함으로써 집단 간의 차이를 명확하게 하였다. 군집 분석 결과 효율성을 추구 형, 군집, Business process 정확성 추구형 집단과 환경 변화 대응 추구형 군집으로 패턴을 나눌 수 있었다. 응답 기업을 Miles와 Snow의 전략유형으로 분류하여 응답 기업의 전략 유형을 판별한 결과 분석자형 40.6%, 방어자형 15.1%, 공격자형 37.2%, 반응자형 6.9%로 조사되었다. 위에서 유형화한 SCM의 활용 패턴과 전략유형을 Matrix화하여 가설인 SCM 활용 패턴과 전략유형의 적합도와 SCM 성과 만족도와의 관계를 검증하였다. 연구를 수행한 결과 기업이 SCM을 활용할 때, SCM 활용 패턴 및 전략 유형에 따라 SCM 성과 만족도가 다르게 나타난다는 것을 알 수 가 있다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.6
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• pp.563-569
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• 2020

Presenting the impact of meteorological disasters departs from the traditional weather forecasting approach for meteorological phenomena. It is important to provide impact forecasts so that precautions against disruption and damage can be taken. Countries such as the United States, the U.K., and France already conduct impact forecasting for heavy rain, heavy snow, and cold weather. This study improves and applies forecasts of the impact of heavy rain among various weather phenomena in accordance with domestic conditions. A total of 33 impact factors for heavy rain were constructed per 1 km grids, and four impact levels (minimal, minor, significant, and severe) were calculated using standard normal distribution. Estimated criteria were used as indicators to estimate heavy rain risk impacts for 6 categories (residential, commercial, utility, community, agriculture, and transport) centered on people, facilities, and traffic.

• Journal of the Korean earth science society
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• v.41 no.1
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• pp.31-39
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• 2020

Cheonji, the largest caldera lake in Asia, is located at the summit of Baekdu Mountain. Cheonji is covered with snow and ice for about six months of the year due to its high altitude and its surrounding environment. Since most of the sources of water are from groundwater, the water temperature is closely related to the volcanic activity. However, in the 2000s, many volcanic activities have been monitored on the mountain. In this study, we analyzed the dimension of ice produced during winter in Baekdu Mountain using Sentinel-1 satellite image data provided by the European Space Agency (ESA). In order to calculate the dimension of ice from the backscatter image of the Sentinel-1 satellite, 20 Gray-Level Co-occurrence Matrix (GLCM) layers were generated from two polarization images using texture analysis. The method used in calculating the area was utilized with the Support Vector Machine (SVM) algorithm to classify the GLCM layer which is to calculate the dimension of ice in the image. Also, the calculated area was correlated with temperature data obtained from Samjiyeon weather station. This study could be used as a basis for suggesting an alternative to the new method of calculating the area of ice before using a long-term time series analysis on a full scale.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.1
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• pp.50-60
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• 2018

In this paper, we developed a broadband multi-layered radome applicable for high-power applications. In this regard, we presented the wave propagation characteristics of the broadband multi-layered radome with the ABCD matrix and obtained the optimal thickness and the material constant for each layer by an optimization algorithm called "particle swarm optimization," implemented by a commercial numerical modeling tool. Further, we redesigned it in view of mechanical properties to reflect environmental conditions such as wind, snow, and ice. The power transmission property was reanalyzed based on the recalculated data of each layer's thickness to consider the limitations of the fabrication of a large structure. Under the condition of a peak electric field strength that is 10 dB above the critical electric field strength in air breakdown, we analyzed the air breakdown by radio frequency(RF) in the designed radome using the commercial full-wave electromagnetic tool. The radome was manufactured and tested by continuous wave(CW) RF small signal and large signal in an anechoic chamber. The test results showed good agreement with those attained by simulation.

• Journal of Korean Society for Atmospheric Environment
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• v.27 no.3
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• pp.313-325
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• 2011

From October 2009 to June 2010, major greenhouse gases (GHG: $N_2O$, $CH_4$, $CO_2$) soil emission were measured from upland cabbage field at Kunsan ($35^{\circ}$56'23"N, $126^{\circ}$43'14"E), Korea by using closed static chamber method. The measurements were conducted mostly from 10:00 to 18:00LST during field experiment days (total 28 days). After analyzing GHG concentrations inside of flux chamber by using a GC equipped with a methanizer (Varian CP3800), the GHG fluxes were calculated from a linear regression of the changes in the concentrations with time. Soil parameters (e.g. soil moisture, temperature, pH, organic C, soil N) were also measured at the sampling site. The average soil pH and soil moisture were ~pH $5.42{\pm}0.03$ and $70.0{\pm}1.8$ %WFPS (water filled pore space), respectively. The ranges of GHG flux during the experimental period were $0.08\sim8.40\;mg/m^2{\cdot}hr$ for $N_2O$, $-92.96\sim139.38mg/m^2{\cdot}hr$ for $CO_2$, and $-0.09\sim0.05mg/m^2{\cdot}hr$ for $CH_4$, respectively. It revealed that monthly means of $CO_2$ and $CH_4$ flux during October (fall) were positive and significantly higher than those (negative value) during January (winter) when subsoil have low temperature and relatively high moisture due to snow during the winter measurement period. Soil mean temperature and moisture during these months were $17.5{\pm}1.2^{\circ}C$, $45.7{\pm}8.2$%WFPS for October; and $1.4{\pm}1.3^{\circ}C$, $89.9{\pm}8.8$ %WFPS for January. It may indicate that soil temperature and moisture have significant role in determining whether the $CO_2$ and $CH_4$ emission or uptake take place. Low temperature and high moisture above a certain optimum level during winter could weaken microbial activity and the gas diffusion in soil matrix, and then make soil GHG emission to the atmosphere decrease. Other soil parameters were also discussed with respect to GHG emissions. Both positive and negative gas fluxes in $CH_4$ and $CO_2$ were observed during these measurements, but not for $N_2O$. It is likely that $CH_4$ and $CO_2$ gases emanated from soil surface or up taken by the soil depending on other factors such as background concentrations and physicochemical soil conditions.