• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.389-392
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• 2004

Classification of Earth natural components within a full polarimetric SAR image is one of the most important applications of radar polarimetry in remote sensing. In this paper, the unsupervised classification algorithms based on the combined use of the polarimetric processing technique such as the target decomposition and statistical complex Wishart classification method are evaluated and applied to vegetated terrain in Jeju volcanic island.

• 한국지구물리탐사학회:학술대회논문집
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• 2001.09a
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• pp.1-13
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• 2001

The role of geophysics in Environmental Earth Sciences and Engineering is considered. In the developing era since 60's in Japan, geophysics has mainly contributed to investigation of new constructions such as tunnels, dams and high-rise buildings. In the coming sustainable era, geophysics must be used for maintaining the safe and easy human life. Application examples of geophysics to investigations for disaster prevention, maintenance of existing constructions and soil and groundwater pollutions are presented to demonstrate their role in Environmental Geo-engineering. Future subjects in this field for geophysics and geophysicists are also discussed.

• Korean Journal of Remote Sensing
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• v.37 no.6_2
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• pp.1819-1827
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• 2021

Land-use/cover change caused by rapid urbanization in South Korea is one of the concerns in flood risk management because groundwater recharge by precipitation hardly occurs due to an increase in impermeable surfaces in urban areas. This study investigated the hydrologic effects of land-use/cover on groundwater recharge in the Yeonje-gu district of Busan, South Korea. A statistical time series analysis was conducted with temporal variations of precipitation and groundwater level to estimate lag-time based on correlation coefficients calculated from auto-correlation function (ACF), cross-correlation function (CCF), and moving average (MA) at five sites. Landform and land-use/cover within 250 m radius of the monitoring wells(GW01, GW02, GW03, GW04, and GW05) at five sites were identified by land cover and digital map using Arc-GIS software. Long lag-times (CCF: 42-71 days and MA: 148-161 days) were calculated at the sites covered by mainly impermeable surfaces(GW01, GW03, and GW05) while short lag-times(CCF: 4 days and MA: 67 days) were calculated at GW04 consisting of mainly permeable surfaces. The results suggest that lag-time would be one of the good indicators to evaluate the effects of land-use/cover on estimating groundwater recharge. The results of this study also provide guidance on the application of statistical time series analysis to environmentally important issues on creating an urban green space for natural groundwater recharge from precipitation in the city and developing a management plan for hydrological disaster prevention.

• Coupled systems mechanics
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• v.7 no.5
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• pp.611-626
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• 2018

We theoretically consider a possible influence of periodic oceanic tides on non-periodic changes in the dynamics of the Earth and Moon over a long time scale. A particular emphasis will be placed on the contribution from rotating tidal waves, which rotate along the inner edge of an oceanic basin surrounded by topographic boundary. We formulate the angular momentum and the mechanical energy of the rotating tidal wave in terms of celestial parameters with regard to the Earth and Moon. The obtained formula are used to discuss how the energy dissipation in the rotating tidal wave should be relevant to the secular variation in the Earth's spin rotation and the Earth-Moon distance. We also discuss the applicability of the formula to general oceanic binary planets subject to tidal coupling.

• Journal of The Korean Astronomical Society
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• v.43 no.6
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• pp.183-190
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• 2010

According to the historical documents and paintings in many civilizations, rocks that fell from the sky fascinated humans as the message from the God or supernaturals. Scientific progress allows humans to recognize these exciting extraterrestrial objects as meteorites. Meteorites contain a wealth of pivotal information regarding formation of the early Solar System. Meteorites also provide broader scientific insights on, for example, the origin of life, interplanetary transfer of life forms, massive depletion of biosphere on Earth, and evolution of lithosphere on Earth-like planetary bodies.

• Journal of Environmental Science International
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• v.25 no.1
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• pp.107-125
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• 2016

Long-term variations of $PM_{10}$ and the characteristics of local meteorology related to its concentration changes were analyzed at 4 air quality sites (Ido-dong, Yeon-dong, Donghong-dong, and Gosan) in Jeju during two different periods, such as PI (2001-2006) and PII (2007-2013), over a 13-year period. Overall, the long-term trend of $PM_{10}$ was very slightly downward during the whole study period, while the high $PM_{10}$ concentrations in PII were observed more frequently than those in PI. The concentration variations of $PM_{10}$ during the study period was clarified in correlation between $PM_{10}$ and meteorological variables, e.g. the low (high) $PM_{10}$ concentration with large (small) precipitation or high (low) radiation and in part high $PM_{10}$ concentrations (especially, Donghong-dong and Gosan) with strong wind speed and the westerly/northwesterly winds. This was likely to be caused by the transport effect (from the polluted regions of China) rather than the contribution of local emission sources. The $PM_{10}$ concentrations in "Asian dust" and "Haze" weather types were higher, whereas those in "Precipitation", "Fog", and "Thunder and Lighting" weather types were lower. The contribution of long-range transport to the observed $PM_{10}$ levels in the urban center (Ido-dong, Yeon-dong, and Donghong-dong), if estimated by comparison to the data of the background site (Gosan), was found to explain about 80% (on average) of its input.

• Economic and Environmental Geology
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• v.49 no.2
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• pp.97-104
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• 2016

Here we firstly present that a timing of reactivated event of Yangsan fault, the major fault in the southeastern Korean Peninsula, by using combined approaches of the optimized illite-polytype quantification, the K-Ar age-dating, and the recently developed illite-age-analysis (IAA) approach for the fault clays from Sangcheon-ri area of Yangsan main fault line. Two chronological record of brittle fault-activation event at about 41.5~43.5 and 50.7 Ma were determined from 3 fault gouges suggesting a crucial reactivation time-scheme. Furthermore, the regional processes that drive tectonics to form and reactivate the Yangsan fault may be explained from the chronological analysis for additional sites along the Yangsan fault.

• Asia-Pacific Journal of Atmospheric Sciences
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• v.54 no.4
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• pp.587-598
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• 2018

The impacts of aerosol loading on surface precipitation from mid-latitude deep convective systems are examined using a bin microphysics model. For this, a precipitation case over north central Mongolia, which is a high-altitude inland region, on 21 August 2014 is simulated with aerosol number concentrations of 150, 300, 600, 1200, 2400, and $4800cm^{-3}$. The surface precipitation amount slightly decreases with increasing aerosol number concentration in the range of $150-600cm^{-3}$, while it notably increases in the range of $600-4800cm^{-3}$ (22% increase with eightfold aerosol loading). We attempt to explain why the surface precipitation amount increases with increasing aerosol number concentration in the range of $600-4800cm^{-3}$. A higher aerosol number concentration results in more drops of small sizes. More drops of small sizes grow through condensation while being transported upward and some of them freeze, thus increasing the mass content of ice crystals. The increased ice crystal mass content leads to an increase in the mass content of small-sized snow particles largely through deposition, and the increased mass content of small-sized snow particles leads to an increase in the mass content of large-sized snow particles largely through riming. In addition, more drops of small sizes increase the mass content of supercooled drops, which also leads to an increase in the mass content of large-sized snow particles through riming. The increased mass content of large-sized snow particles resulting from these pathways contributes to a larger surface precipitation amount through melting and collision-coalescence.

• Journal of Microbiology and Biotechnology
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• v.33 no.8
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• pp.1084-1090
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• 2023

The strain KIST612, initially identified as E. limosum, was a suspected member of E. callanderi due to differences in phenotype, genotype, and average nucleotide identity (ANI). Here, we found that E. limosum ATCC 8486^T and KIST612 are genetically different in their central metabolic pathways, such as that of carbon metabolism. Although 16S rDNA sequencing of KIST612 revealed high identity with E. limosum ATCC 8486^T (99.2%) and E. callanderi DSM 3662^T (99.8%), phylogenetic analysis of housekeeping genes and genome metrics clearly indicated that KIST612 belongs to E. callanderi. The phylogenies showed that KIST612 is closer to E. callanderi DSM 3662^T than to E. limosum ATCC 8486^T. The ANI between KIST612 and E. callanderi DSM 3662^T was 99.8%, which was above the species cut-off of 96%, Meanwhile, the ANI value with E. limosum ATCC 8486^T was not significant, showing only 94.6%. The digital DNA-DNA hybridization (dDDH) results also supported the ANI values. The dDDH between KIST612 and E. callanderi DSM 3662^T was 98.4%, whereas between KIST612 and E. limosum ATCC 8486^T , it was 57.8%, which is lower than the species cut-off of 70%. Based on these findings, we propose the reclassification of E. limosum KIST612 as E. callanderi KIST612.

• Journal of the Mineralogical Society of Korea
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• v.24 no.4
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• pp.321-325
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• 2011