• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.64-72
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• 2007

Nationwide occurrence of arsenic in groundwater of Korea was investigated with the data from the groundwater quality monitoring stations. During 2001-2006, As has been quantitatively detected in 3.0 % of the total wells $(5.0{\sim}188{\mu}g/L)$, and its geographical distribution suggests 3 groups: an urbanized and industrialized area (Seoul and its neighbouring province), and two naturally occurring areas (Chungbuk and Gyeongnam provinces). Natural occurrence of As appears to be geologically related with Ogcheon metasedimentary rocks and Cretaceous volcanic rocks. Based on the results of the previous studies in the high As sites, the oxidation of sulfides can be a major control on As concentrations in groundwater in the mineralized and altered zone within the area of Cretaceous volcanic rocks. Desorption process under slightly high pH conditions may also be responsible for high As in groundwater in areas of Ogcheon metasedimentary rocks.

• Proceedings of the Petrological Society of Korea Conference
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• 2009.05a
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• pp.153-153
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• 2009

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.153-154
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• 2019

본 연구에서는 일본 기상청(JMA)에서 제공하는 JMA-MSM (Meso-Scale Model) 바람장을 SWAN 모델에 입력자료로 적용하여 파랑전파를 모의하였다. 영역은 심해역·중간역·연안역으로 설정하였다. 산출된 모델링의 결과는 관측자료와 비교·검증하여 모델 구축에 대한 신뢰성을 확보하였다. 그리고 연안역에서 SWAN모델의 파랑스펙트럼정보를 입력조건으로 하는 SWASH모델의 영역을 구축하여 두 모델간 파랑전파양상을 비교하였다. SWAN(phase-averaged) 모델과 SWASH(phase-resolving) 모델은 지배방정식의 차이에 따라 파랑의 위상처리 방식 등의 차이가 있다. 이로 인한 연안역에서의 파랑전파양상의 차이를 비교하였다.

• The Journal of the Acoustical Society of Korea
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• v.37 no.3
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• pp.139-146
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• 2018

Monostatic sonar systems localize targets using the time information of pulse transmission and receipt. Whereas, in asynchronous bistatic sonar systems, receivers need to detect direct blast to localize targets, since a source doesn't share pulse information with receivers. In this paper, we propose a direct blast detection algorithm, which estimates PRI (Pulse Repetition Interval) of direct blast and adaptive thresholds. Experimental results show the proposed algorithm has robust direct blast detection performance in the environment where strong background noise and target signal exist.

• Proceedings of the Petrological Society of Korea Conference
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• 2004.05a
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• pp.74-74
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• 2004

• Proceedings of the Mineralogical Society of Korea Conference
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• 2004.05a
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• pp.74-74
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• 2004

• Proceedings of the KOR-BRONCHOESO Conference
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• 1993.05a
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• pp.92-92
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• 1993

It is generally agreed that cellular immune functions are damaged by radiation therapy(RT). However, the exact effects of RT on peripheral lymphocytes are not yet clear. Authors previously reported the radiation effects on lymphocytes subpopulations, but these results merely showed the alteration of proportion of lymphocytes subpopulations after RT. So we try to evaluate the number of lymphocytes in each subpopulations as well as the proportion of subpopulations, and the recovery patterns of these alterations by time duraion after RT. The result shows that the proportion of subpopulations and number of lymphocytes in each subpopulations are decreased after RT except natural killer cells(NK cells), which proportion is increased but number is not changed, and these changes are stationary continued for post RT 6 months and then gradually recovered. However, the radiation effects on peripheral lymphocytes still remain after one year.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.1
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• pp.98-103
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• 2017

In this paper, determination method for drag force and drag coefficient from results of firing test is described. The drag force and drag coefficient are determined through inverse operation of 2-dimensional projectile equation of motion. Determination method was verified by comparing analytical drag coefficient with data from flight test. Analysis of drag coefficient and drag reduction was performed with the data of flight test using artillery projectiles with base bleed unit.

• Journal of Conservation Science
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• v.25 no.2
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• pp.131-145
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• 2009

Goryeong Yangjeondong Petroglyph on the joint face of the bedrock (6m in width, 3m in height) composed of the green sandstone has circles and shield pattern sculptures. The rock is mainly composed of quartz, feldspar, chlorite, illite and calcite with the clay minerals. These clay minerals occur as pore lining, replacement of component and pore fillings. Investigated the weathering aspects including the connection between soluble salt and rock weathering and the stability of the bedrock with petroglyphs. The Major deterioration aspect are grain peel-off, surface exfoliation, cracks and damage. And the bedrock where the joints and cracks advance is interpreted with the fact that has the possibility of the falling rock. For conservation, adhesive need to cover crack and damage and consolidation is necessary in the surface which becomes weak.

• Journal of the Mineralogical Society of Korea
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• v.1 no.2
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• pp.104-116
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• 1988

Berthierine and Nontronite are firstly identified in the Sangdong tungsten ore deposits. Quantitative and qualitative analyses by EPMA and the studies using X-ray diffraction, transmission electron microscopy, and infrared absorption spectroscopy were done to characterize berthierine and nontronite. The data from berthierine are in good agreement with those from other localities. The structural data of the Sangdong berthierine are consistent with the orthorhombic, pseudo-hexagonal form which is more common in samples with high $SiO_2$ and low $Al_2O_3$ content. Geologic features suggest that the Sangdong berthierine is diagenetic in origin. However, nontronite might be a product of hydrothermal alteration after the tungsten mineralization.