• Korean Journal of Remote Sensing
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• v.35 no.6_3
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• pp.1221-1233
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• 2019

Estimating damage in each sector that can be caused by volcanic ash deposition, is very important to prepare the volcanic ash disaster. In this study, we showed predicted-Korean-volcanic-ash damage of each sector by using volcanic ash diffusion simulation and spatial-data-based volcanic ash damage sector in previous study. To this end, volcanic ash related base maps were generated by collecting and processing spatial information data. Finally, we showed Korean-volcanic-ash-deposition damages by sector using the collected Mt. Aso volcanic ash scenarios via overlapping analysis. As a result, volcanic-ash-related damages were expected to occur in the 162 and 134 districts for each Aso volcanic ash scenarios, since those districts exceeds the minimum volcanic ash damage criterion of 0.01 mm. Finally, we compared possible volcanic ash damages by sectors using collected and processed spatial data, after selecting administrative districts(Scenario 190805- Kangwon-do, Kyungsangbuk-do; Scenario 190811-Chuncheon-si, Hongcheon-si) with the largest amount of volcanic ash deposition.

• Korean Journal of Remote Sensing
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• v.34 no.6_4
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• pp.1519-1529
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• 2018

The volcanic ash can spread out over hundreds of kilometers in case of large volcanic eruption. The deposition of volcanic ash may induce damages in urban area and transportation facilities. In order to respond volcanic hazard, it is necessary to estimate efficiently the diffusion area of volcanic ash. The purpose of this study is to compare in-situ volcanic deposition and satellite images of the volcanic eruption case. In this study, we used Near-Infrared (NIR) channels 7 and 8 of Geostationary Ocean Color Imager (GOCI) images for Mt. Aso eruption in 16:40 (UTC) on October 7, 2016. To estimate deposit area clearly, we applied Principal Component Analysis (PCA) and a series of morphology filtering (Eroded, Opening, Dilation, and Closing), respectively. In addition, we compared the field data from the Japan Meteorological Agency (JMA) report about Aso volcano eruption in 2016. From the results, we could extract volcanic ash deposition area of about $380km^2$. In the traditional method, ash deposition area was estimated by human activity such as direct measurement and hearsay evidence, which are inefficient and time consuming effort. Our results inferred that satellite imagery is one of the powerful tools for surface change mapping in case of large volcanic eruption.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.26 no.1
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• pp.187-198
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• 2000

Chitosan oligosaccharide with an average degree of polymerization 2-3 was prepared by degradation reaction using sodium nitrite, and the resulting aldehyde group was reduced to hydroxy group. N-palmitoyl, O-palmitoyl chitosan oligosaccha was obtained from the reaction between palmitoyl chloride and oligosaccharide under DMAP catalyst. Alkaline hydrolysis was carried out to remove the O-palmitoyl group. After dispersion and ultrasonication in aqueous solution, N-palmitoyl chitosan oligosaccharide gives vesicle structure. Its structure and size was analyzed by TEM.

• Journal of the Korean earth science society
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• v.38 no.2
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• pp.115-128
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• 2017

Aso caldera volcano is located in central Kyushu, Japan which is one of the largest caldera volcanoes in the world. Nakadake crater is the only active central cone in Aso caldera. There was an explosive eruption on October 8, 2016, the eruption column height was 11 km, and fallout ash was found 300 km away from the volcano. In this study, we performed a numerical simulation to analyze the ash dispersion and the fallout tephra deposits during this eruption using Ash3D that was developed by the United States Geological Survey. The result showed that the ash would spread to the east and northeast, that could not affect the Korean peninsula, and the volcanic ash was deposited at a place from a distance of 400 km or more in the direction of east and northeast. The result was in close agreement with the identified ashfall deposits. Ash3D can be useful for quick forecast for the effects of hazards caused by volcanic ash.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.2
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• pp.50-50
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• 2018

한국의 근현대 천문학은 조선시대 관상감의 명맥을 잇고 천문학의 현대화를 이루는 과정에서 역사적이고 문화적인 자료를 남겼다. 그 중 국립천문대를 거쳐 한국천문연구원에 이르기까지 주요 연구 결과물은 국가적 차원에서 보존해야 할 가치 있는 기록물들이다. 이들은 연구 환경변화의 주요 인물과 스토리까지 포괄하고 있으므로 그 과정에서 파생된 소산물도 체계적으로 조직화하여 대중에게 서비스할 필요가 있다. 이 기획 연구는 도큐멘테이션 전략과 사료 콘텐츠 세트 개발 방법론을 활용하여 한국 근현대 천문학 기록물을 수집하고 주제별로 재가공하는 절차를 제시한다. 도큐멘테이션 전략은 국내외에 산발적으로 분산된 한국 근현대 천문 사료의 유형과 지역 등 편중성을 가려내어 중복된 기록물은 걸러내고 희소성 높은 기록물을 선별하여 수집하는 방법론이다. 천문 사료 콘텐츠 세트는 한국천문학사의 주요 인물과 천문대 등 학술적, 문화적으로 가치 있는 주제를 중심으로 본(本) 기록물과 연관 기록물을 맥락적으로 관리 서비스할 수 있는 방법론이다. 이 연구를 통하여 초중등 교과 과정이나 유관 기관과 서비스를 연동하여 한국천문지식정보의 범용화와 천문 아카이브에 대한 대중의 접근 편의를 도모할 수 있을 것으로 기대된다.

• Korean Journal of Remote Sensing
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• v.35 no.5_1
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• pp.751-761
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• 2019

Mt. Baekdu, Mt. Aso, Mt. Sakurajima, Mt. Kikai and etc are distributed around the Korean Peninsula. Recently signs of eruption of Mt. Baekdu are increasing, raising concerns over possible damage to volcanic ash from seasonal winds during the winter eruption. Therefore, detailed procedures for investigation and countermeasures for volcanic ash spread and damage are required. But the standards for the warning and alarm signal of volcanic ash presented by Korea Ministry of Government Legislation are vague, with "when damage is expected" and "when serious damage is expected". In this study, to analyze the damage threshold and to apply the cases of overseas damage to the country, a survey was conducted on the establishment of domestic spatial information by public institutions with public confidence. As a result of the investigation of damage from volcanic ash overseas, the details of the damage cases were different depending on the type of life or income sources of each country. Therefore, instead of applying the volcanic ash damage cases abroad in Korea, spatial information analysis was performed to reflect domestic social and natural characteristics. In addition, we selected the areas to be considered in the event of volcanic ash damage in Korea. Finally, domestic volcanic ash damages should be classified as health, residential, road, railroad, aviation, power, water, agriculture, livestock, forest, and soil. When establishing the volcanic ash alarm optimized for Korea in the future, overseas volcanic ash damage cases and domestic spatial information construction in this study will be helpful in policy establishment.

• Korean Journal of Plant Taxonomy
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• v.37 no.1
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• pp.41-59
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• 2007

This study was to establish the floristic composition of northern region in Gyeonggi-Province area($126^{\circ}45^{\prime}-127^{\circ}37^{\prime}E$, $37^{\circ}31^{\prime}-38^{\circ}17^{\prime}N$). This work was investigated from April, 1988 to October, 2004. The flora of vascular plants of northern region in Gyeonggi-Province were consisted of total 2,030 taxa; 145 families, 656 genera, 1,611 species, 7 subspecies, 320 varieties, 1 subvarieties and 91 formae. Among them, Korean endemic species were composed of 46 families, 85 genera, 84 species, 35 varieties, 1 subvarieties, and 18 formae, total 138 taxa. The rare and endangered plants based on floral region indicated by Ministry of Environment were 416 taxa; V rank species 18 taxa, IV rank species 79 taxa, III rank species 111 taxa, II rank species 80 taxa, I rank species 128 taxa. Also the naturalized plants were 114 species, correspond to 39.7% of among total 287 species appeared in South Korea. the result of PCA, Gwangju mountain chain at northern region of Gyeonggi-Province has rich and diverse vascular plants, and there are many Korean endemic, rare and endangered plants. therefore Gwangju mountain chain must be the core axis in for conserving the plant biodiversity and richness.

• The Journal of the Petrological Society of Korea
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• v.25 no.3
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• pp.195-209
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• 2016

The understanding of geometric complexity of strike-slip Fault system can be an important factor to control fault reactivation and surface rupture propagation under the regional stress regime. The Kumamoto earthquake was caused by dextral reactivation of the Futagawa-Hinagu Fault system under the E-W maximum horizontal principal stress. The earthquakes are a set of earthquakes, including a foreshock earthquake with a magnitude 6.2 at the northern tip of the Hinagu Fault on April 14, 2016 and a magnitude 7.0 mainshock which generated at the intersection of the two faults on April 16, 2016. The hypocenters of the main shock and aftershocks have moved toward NE direction along the Futagawa Fault and terminated at Mt. Aso area. The intersection of the two faults has a similar configuration of ${\lambda}$-fault. The geometries and kinematics, of these faults were comparable to the Yansan-Ulsan Fault system in SE Korea. But slip rate is little different. The results of age dating show that the Quaternary faults distributed along the northern segment of the Yangsan Fault and the Ulsan Fault are younger than those along the southern segment of the Yansan Fault. This result is well consistent with the previous study with Column stress model. Thus, the seismic activity along the middle and northern segment of the Yangsan Fault and the Ulsan Fault might be relatively active compared with that of the southern segment of the Yangsan Fault. Therefore, more detailed seismic hazard and paleoseismic studies should be carried out in this area.

• Journal of the Korean earth science society
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• v.21 no.6
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• pp.703-718
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• 2000

In order to investigate interannual variation of total ozone and reflectivity over the globe, Nimbus-7/TOMS data were used on the monthly mean and its anomaly for the period of 1979-92. This study also examined MSU channel 4(Ch4; lower-stratosphere) brightness temperature data and two model reanalyses of NCEP and GEOS to compare the ozone variation with atmospheric thermal condition. In addition, the MSU channel 1(Ch1 ; lower-troposphere) brightness temperature was used to compare with the reflectivity. The ozone showed strong annual cycle with downward trend(-6.3${\pm}$0.6 DU/decade) over the globe, and more distinct response to volcanic eruption than El Ni${\tilde{n}$o. The relationship between total ozone and MSU Ch4 observation, and between the ozone and model reanalyses of lower stratosphere temperature showed positive correlation(0.2-0.7) during the period of 1980-92. Reflectivity increased interannually by 0.2${\pm}$0.06%/decade over the globe during the above period and reflected El Ni${\tilde{n}$o(1982-83, 1991-92) well. Its variability in annual cycle was remarkably smaller in tropics than in higher latitudes. This is inferred due to cloud suppression and tropical upwelling regions. Reflectivity correlated negatively(-0.9) to the Ch1 temperature over the globe, but positively(0.2) over tropical ocean. The positive value over the ocean results from the effect of microwave emissivity which increases the Ch1 temperature with enhanced hydrometeor activity. Significant correlations between total ozone and the Ch4 temperature, and between reflectivity and the Ch1 Suggest that the TOMS data may use valuably to better understand the feedback mechanism of climate change.