• Korean Journal of Remote Sensing
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• v.34 no.6_4
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• pp.1503-1517
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• 2018

Mt. Baekdu is a stratovolcano located at the border between China and North Korea and is known to have formed through its differentiation stage after the Oligocene epoch in the Cenozoic era. There has been a growing interest in the magma re-activity of Mt. Baekdu volcano since 2010. Several research projects have been conducted by government such as Korea Meteorological Administration and Korea Institute of Geoscience and Mineral Resources. Because, however, the Mt. Baekdu volcano is located far from South Korea, it is quite difficult to collect in-situ observations by terrestrial equipment. Remote sensing is a science to analyze and interpret information without direct physical contact with a target object. Various types of platform such as automobile, unmanned aerial vehicle, aircraft and satellite can be used for carrying a payload. In the past several decades, numerous volcanic studies have been conducted by remotely sensed observations using wide spectrum of wavelength channels in electromagnetic waves. In particular, radar remote sensing has been widely used for volcano monitoring in that microwave channel can gather surface's information without less limitation like day and night or weather condition. Radar interferometric technique which utilized phase information of radar signal enables to estimate surface displacement such as volcano, earthquake, ground subsidence or glacial movement, etc. In 2018, long-term research project for collaborative observation for Mt. Baekdu volcano between Korea and China were selected by Korea government. A volcanic specialized research center has been established by the selected project. The purpose of this paper is to introduce about remote sensing techniques for volcano monitoring and to review selected studies with remote sensing techniques to monitor Mt. Baekdu volcano. The acquisition status of the archived observations of six synthetic aperture radar satellites which are in orbit now was investigated for application of radar interferometry to monitor Mt. Baekdu volcano. We will conduct a time-series analysis using collected synthetic aperture radar images.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.144-157
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• 2009

Nondestructive methods to check the vitality of trees and to find out internal decay of old-giant trees include the use of electrical resistance, ultrasound transmission time, microdrilling, and infrared thermography etc. Among these, ultrasound transmission offers some advantages compared to others such as it is an entirely nondestructive detection method and it can be applied to very big trees. However, the ultrasound equipment is comparatively expensive and not broadly spread yet. On the other hand, Shigometer is versatile to be applied to check vitality of the tree and find out internal decay. Electrical conductivity of plant tissues is a very useful characteristics to determine the vitality and internal decay of trees. Electrical resistance of cambial area tells about the vitality of a tree and electrical resistance of heartwood reveals discoloration or decay of it. For determination of the vitality of the tree, the standard equation for calibration of measured electrical resistances should be developed by measuring and analyzing electrical resistance from at least 30-40 trees of the same species with that tree. All the factors, especially tree species, diameter of the stem, and temperature, which can altered the electrical resistance of trees, should be taken into consideration in the development of the equation. If the standard equation is developed for old-giant trees that we should conserve, it will be very useful. In addition, periodical and continued measuring of a certain tree will help to determine the condition of the tree by comparing the measurement with accumulated data of the tree. Measuring electrical resistance of wood might not require the standard equation. But it also needs to check electrical resistance of sound wood of the same tree species. If the stems that should be examined is thicker than 40cm, it is better to use the ultrasound measurement combined to Shigometer.

• Korean Journal of Heritage: History & Science
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• v.45 no.3
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• pp.160-173
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• 2012

Roofing tile research conducted in Korea so far is mostly related to studies on roofing tile patterns excavation report on the roof tile klin site in the aspects of archeology architecture and history of art. There have been continuous studies on kiln ground and manufacture techniques of roofing tiles. However it is difficult to find roofing tiles research based on scientific experiments. The research on this paper performs physical and chemical experimental study to understand order, manufacturing techniques and other characteristics of Chosun Dynasty roofing tiles excavated in Dongdaemun stadium. As for physical experimental study water absorption, specific gravity, whole-rock Magnetic susceptibility rate and Differential Thermal Analysis are conducted. As for chemical experimental study, neutron activation analysis(NAA), microstructure observation, X-ray diffractometry(XRD) analysis are conducted. Result of neutron activation analysis and statistical analysis on piece of roof tile 22 samples clearly show that the roofing tile samples are from different time line and places. It also shows different composition when compare average value of rare earth resources per findspots. It means roofing tiles were manufactured from clay mineral from several places. Close inspection using XRD and polarization microscope reveals that main components of roofing tiles are quartz and felspar. Mica and Illite are found partially. XRD analysis shows mullite mineral composition which occurs when roofing tile is calcined around $1000^{\circ}C$. Differential thermal analysis shows gradual exothermic peak near $900^{\circ}C$. Based on these results, it is assumed that roofing tile is made at $900{\sim}1000^{\circ}C$. result of XRD analysis shows mullite were made near $1000^{\circ}C$. in Differential Thermal Analysis shows gradual exothermic peak near $900^{\circ}C$. this results shows that roof tiles were made near 900~1000 near $1000^{\circ}C$ mean value of whole-rock Magnetic susceptibility rate. When performed comparative analysis using whole-rock Magnetic susceptibility rate average value, findspots provided no certain classification to arrange. Nonetheless low whole-rock Magnetic susceptibility rate 0.2~0.78(${\times}103$ SI unit) is found when roofing tile patterns are Pasangmun, Taesangmun, Eosangmun, Kyukjamun, Heongsunmun. Overall absorptivity is 14~21%. It is similar to 14~18% of roofing tile from Chosun Dynasty. There is only 1.4~2.5g/cm3 of roof tile sample specific gravity. The analysis finds no difference in specific gravity by findspots.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.108-125
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• 2013

This study examined the actual reconstruction drawing, composite mineral, particle size and property test, fine organic matters, color differences and main ingredients of the earthen mold excavated in Dongcheon-dong, Gyungju. The cross-section of the inner mold and outer mold divides into inside (1st layer) and outside (2nd layer), with organic matters mixed outside. The cross-section has been altered due to heat and form removal agent. X-ray analysis revealed that the layer was made of minerals with high transmissivity and only quartz particles were observed through a polarizing microscope. The inside of cross-section in SEM observation identified enlarged air gap, with crack developed in the center, but no changes observed on the outside. The particle size of the composites is almost the same for the inner mold and outer mold and is silt clay loam. The ratio between silt clay and silt clay loam was about 2.7:1 and 2.9:1 respectively. In the property test, the density and absorption rate of inner mold and outer mold were similar, but porosity was different, with inner mold of 27.36% and outer mold of 31.09%. The color difference of cross-section seems to have been caused by the spread of soot on the 1st layer surface for removal of form or by the covering of ink to protect the 1st layer. Composite mineral analysis revealed the same composition for the inner mold and outer mold, except for the magnetite that was detected in the inner mold alone. As for the main ingredient analysis, the average content of $SiO_2$ was 71.64% and that of $Al_2O_3$ was 14.59%. As for the sub-ingredients, $Fe_2O_3$ was 4.51%, $K_2O$ 3.06%, $Na_2O$, MgO, CaO, $TiO_2$, $P_2O_5$ and MnO was less than 2%.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.66-83
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• 2018

This article focuses how the materials of hatstrings of the 19th to 20th century gat, the Korean top hat for men among the collections of National Folk Museum of Korea, was transformed after port opening treaties with overseas since 1876. As a result of analyzing the materials of the hatstrings, amber, tortoiseshell, wood and bamboo as the traditional materials were used, and ivory, glass (soda glass, lead glass, alkali mixed glass) and plastics (cellulose nitrate, phenol-formaldehyde, polystyrene, acryl) were newly used for the hatstrings. Bamboo, wood and amber were the most frequently used materials. Bamboo was mainly used for the pipe of hatstring and were combined with beads and central decorations of other materials. This shows the trend of bamboo hatstring according to the simplification of the clothing and the culture by Regent Heungseon Daewongun. Ambers were used in the central decorations and beads and the origin of ambers was baltic amber just like the amber relics found in Korea. Compositions of glass were soda glass and alkali mixed glass which were excavated or handed down in Korea from ancient times to Joseon dynasty. But in the case of lead glass, Na2O was detected and it is considered to be a new type lead glass for crafts which came from overseas after port opening since 1876 because it showed the characteristic that it deviates from the lead glass component found in Korea. Plastics such as cellulose nitrate and phenol-formaldehyde were used as new synthetic materials to replace traditional materials such as tortoiseshell, amber, and coral as in the West. Cracks, crazing, crumbly and yellowing of cellulose nitrate of hatstrings were observed by deterioration. The survey of the materials of the 19th to 20th century hatstrings among the collections of National Folk Museum of Korea showed that the introduction of new materials such as glass and plastics were used to replace natural materials such as tortoiseshell and amber along with the use of traditional materials after port opening since 1876.

• Journal of the Korean earth science society
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• v.40 no.3
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• pp.227-239
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• 2019

Heavy snowfall events frequently occur in the Gangwon province, and the snowfall amount significantly varies in space due to the complex terrain and topographical modulation of precipitation. Understanding the spatial characteristics of heavy snowfall and its prediction is particularly challenging during snowfall events in the easterly winds. The easterly wind produces a significantly different atmospheric condition. Hence, it brings different precipitation characteristics. In this study, we have investigated the microphysical characteristics of snowfall in the windward and leeward sides of the Taebaek mountain range in the easterly condition. The two snowfall events are selected in the easterly, and the snow particles size distributions (SSD) are observed in the four sites (two windward and two leeward sites) by the PARSIVEL distrometers. We compared the characteristic parameters of SSDs that come from leeward sites to that of windward sites. The results show that SSDs of windward sites have a relatively wide distribution with many small snow particles compared to those of leeward sites. This characteristic is clearly shown by the larger characteristic number concentration and characteristic diameter in the windward sites. Snowfall rate and ice water content of windward also are larger than those of leeward sites. The results indicate that a new generation of snowfall particles is dominant in the windward sites which is likely due to the orographic lifting. In addition, the windward sites show heavy aggregation particles by nearby zero ground temperature that is likely driven by the wet and warm condition near the ocean.

• Korean Journal of Heritage: History & Science
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• v.51 no.2
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• pp.78-91
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• 2018

Sangjogam, located in Goseong, Gyeongsangnam-do, was designated as Natural Monument #411, because of its diverse geological heritage, such as fossils, ripple marks, dykes, and columnar joints. In the area, Byeongpungbawi, with its beautiful columnar joints vertical to the bedding plane of the underlying sedimentary rocks and spectacular coastal view, was named after its overall shape reminiscent of a huge folding screen. The purpose of this study was to investigate the formation process of the columnar joints using the anisotropy of magnetic susceptibility (AMS) method. AMS measurements showed that the k1 and k3 values representative of directions of the long and short axes of a magnetic particle at each point strongly clustered, and the oblate magnetic foliation structure in Byeongpungbawi developed during sill-type intrusion rather than lava flow. In summary, Byeongpungbawi was produced by sill-type intrusion along the bedding plane of the underlying sedimentary layer, and the subsequent formation of columnar joints was accompanied by the cooling and contraction of intruding rhyolite magma. This study potentially provides a basic research tool in understanding the formation mechanism of columnar joints which are widely distributed in southern Korea.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.271-282
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• 2019

This study was conducted to evaluate physiological activity of Robinia pseudo-acacia leaf and its skin penetration using polymer micelles and skin penetrating peptide. After extraction with Robinia pseudo-acacia using the ethanol and distilled water, various physiological activities were examined. The total concentration of polyphenol compounds was determined to be 47.42 mg/g (ethanol extract), 56.88 mg/g (hydrothermal extract) and DPPH radical scavenging ability at $1,000{\mu}g/mL$ was 44.24% in ethanol extract and it is higher than value(41.50%) in hydrothermal extract. The elastase inhibitory assay showed concentration dependence and elastase inhibition of Robinia pseudo acacia leaf ethanol extract was 54.09%, which was the highest at $500{\mu}g/mL$. In the SOD-like experiments, the concentration-dependent results were showed and the SOD-like activity of the Robinia pseudo-acacia leaf ethanol extract was higher than that of the Robinia pseudo acacia leaf hydrothermal extract at all concentrations. At a concentration of $500{\mu}g/mL$, Robinia pseudo acacia leaf ethanol extract showed the highest SOD-like activity of 76.41%. The tyrosinase inhibition at $20{\mu}g/mL$ was determined to be 56.47% (ethanol extract), 23.05% (hydrothermal extract). In the antimicrobial experiments, the hydrothermal extract had no effect, but ethanol extract represented maximum clear zone of 11.00 mm in Propionbacterium acnes strain and maximum clear zone of 10.50 mm. in Bacillus subtilis strain. To solve the problem of insolubility and to improve skin penetration, PCL-PEG polymer micelles containing Robinia pseudo-acacia leaf ethanol extracts and 1.0% cell permeable peptide, hexa-D-arginine (R6) were successfully prepared with particle size of 108.23 and 126.47 nm and excellent skin permeation effects could be showed.

• The Journal of the Petrological Society of Korea
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• v.28 no.3
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• pp.171-193
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• 2019

This study aims to identify the geometry and internal structures of the Yeongdeok Fault, a branch fault of the Yangsan Fault, by detailed mapping and to characterize its kinematics by analyzing the attitudes of sedimentary rocks adjacent to the fault, slip data on the fault surfaces, and anisotropy of magnetic susceptibility (AMS) of the fault gouges. The Yeongdeok Fault, which shows a total extension of 40 km on the digital elevation map, cuts the Triassic Yeongdeok Granite and the Cretaceous sedimentary and volcanic rocks with about 8.1 km of dextral strike-slip offset. The NNW- or N-S-striking Yeongdeok Fault runs as a single fault north of Hwacheon-ri, Yeongdeok-eup, but south of Hwacheon-ri it branches into two faults. The western one of these two faults shows a zigzag-shaped extension consisting of a series of NNE- to NE- and NNW-striking segments, while the eastern one is extended south-southeastward and then merged with the Yangsan Fault in Gangu-myeon, Yeongdeok-gun. The Yeongdeok Fault dips eastward with an angle of > $65^{\circ}$ at most outcrops and shows its fault cores and damage zones of 2~15 m and of up to 180 m wide, respectively. The fault cores derived from several different wall rocks, such as granites and sedimentary and volcanic rocks, show different deformation patterns. The fault cores derived from granites consist mainly of fault breccias with gouge zones less than 10 cm thick, in which shear deformation is concentrated. While the fault cores derived from sedimentary rocks consist of gouges and breccia zones, which anastomose and link up each other with greater widths than those derived from granites. The attitudes of sedimentary rocks adjacent to the fault become tilted at a high angle similar to that of the fault. The fault slip data and AMS of the fault gouges indicate two main events of the Yeongdeok Fault, (1) sinistral strike-slip under NW-SE compression and then (2) dextral strike-slip under NE-SW compression, and shows the overwhelming deformation feature recorded by the later dextral strike-slip. Comparing the deformation history and features of the Yeongdeok Fault in the study area with those of the Yangsan Fault of previous studies, it is interpreted that the two faults experienced the same sinistral and dextral strike-slip movements under the late Cretaceous NW-SE compression and the Paleogene NE-SW compression, respectively, despite the slight difference in strike of the two faults.

• Korean Journal of Heritage: History & Science
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• v.39
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• pp.219-242
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• 2006

Quantitative analysis and provenance interpretation of the raw materials for the jade (amazonite) excavated from the Asan Sijeonri site were studied. Geology of the Sijeonri site composed mainly of Precambrian metasedimentary rocks and the alluvium ranges extensively. In the site, amazonite jade was excavated in the Bronze Age No. 4 circular-shaped resident site. The jade has a comma-shaped and shows light green color with so much cracks. The jade is silicate mineral of columnar habits that is shown white streak, and has fine cleavages with vitreous luster. As the analytical results, this jade was identified as a feldspar-group mineral gemologically called amazonite that is mineralogically microcline formed to intergrowth of albite and orthoclase. Internal textures of the amazonite present Na-end member of albite coexisting with K-end member of orthoclase that are replaced each other along the cleavages and twin planes with several ${\mu}m$ scales. Therefore, the amazonite is one mineral phase combined with albite and orthoclase by substitution of $Na_2O$ and $K_2O$, respectively. The Danyang are is an unique producing site of amazonite in South Korea, and Gongju Janggimyeon was known as microcline provenance to the utmost area from the Sijeonri site. In the marginal area of southern coast in Korean Peninsula, Bronze Age amazonite has been excavated in several sites, where original provenance of the raw amazonite is not identified. The Sijeonri site does not show any facilities of producing and processing traces for amazonite jade. Also, only one jade was collected in the Sijeonri site. Therefore, there is not possibility that the provenance of raw jade is the Sijeonri area. To explain original provenance of the amazonite jade, migration path, manufacturing process and archaeological interpretation are required.