• Economic and Environmental Geology
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• v.50 no.6
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• pp.517-523
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• 2017

A linear relationship between two stable water isotopes, oxygen and hydrogen, has been used to understand the water cycle as a basic tool. A slope and intercept from the linear relationship indicates what kind of physical processes occur during movement of water. Traditionally, ordinary least squares (OLS) method has been utilized for the linear relationship, but total least squares (TLS) method provides more accurate slope and intercept theoretically because isotopic compositions of both oxygen and hydrogen have uncertainties. In this work, OLS and TLS were compared with isotopic compositions of snow and snowmelt collected from the King Sejong Station, Antarctica and isotopic compositions of water vapor observed by Lee et al. (2013) in the western part of Korea. The slopes from the linear relationship of isotopic compositions of snow and snowmelt at the King Sejong Station were estimated to be 7.00 (OLS) and 7.16(TLS) and the slopes of stable water vapor isotopes were 7.75(OLS) and 7.87(TLS). There was a melting process in the snow near the King Sejong Station and the water vapor was directly transported from the ocean to the study area based on the slope calculations. There is no significant difference in two slopes to interpret the physical processes. However, it is necessary to evaluate the slope differences from the two methods for studies for example, groundwater recharge processes, using the absolute slope values.

• Applied Biological Chemistry
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• v.30 no.2
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• pp.118-125
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• 1987

Three rice varieties of Akibare (japonica), Milyang 30 (indica) and Taebaeg (indica) were investigated for their changes in sensory and physical qualities of cooked rices during storage at the temperature range of $4^{\circ}C$ and $70^{\circ}C$ for 25 hours, The qualities studied were sensory attributes of texture which were evaluated by multiple comparison method and physical characteristics of texture measured using with rheometer. Physical Properties of hardness, adhesiveness and elasticity of cooked rices were found to be different among the rice varieties and were affected by storage conditions. Higher values in hardness and elasticity and lower values in adhesiveness were measured for cooked rices of Akibare immidiately after cooking. Those physical values were changed by a steady decrease in hardness and elasticity and increase in adhesiveness during storage for 25 hours. Correlations between sensory and physical characteristics of texture was found a significant relationships between gumminess and hardness (r=0.696), gumminess and adhesiveness (r=-0.800) and gumminess and elasticity (r=0.806).

• Publications of The Korean Astronomical Society
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• v.27 no.2
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• pp.29-37
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• 2012

In this paper, we study the structure of the Daegyupyo (大圭表, Large Gnomon) of the early Joseon dynasty. A Gyupyo (圭表, Gnomon that is Guibiao as pronounced in Chinese) is composed of a Pyo (表, Biao as pronounced in Chinese) making a shadow and a Gyu (圭, Gui as pronounced in Chinese) measuring its length. It is known that the Daegyupyo with the 40-feet height was constructed between the sixteenth to seventeenth year of the King Sejong reign (1444 - 1445) on the basis of the record of Yuanshi (元史, the History of the Yuan Dynasty). By analyzing historical documents such as Joseonwangjosillok (朝鮮王朝實錄, the Annals of the Joseon Dynasty), Yuanshi, and Jegaryeoksangjip (諸家曆象集, a work written by Sunji Lee), we found a possibility that the Ji (池, a pond) on the Gyu was located in the north side of the Pyo. This structure is different from that in previous studies, but is in a good agreement with that of the 40-feet Guibiao remaining in Dengfeng (登封) of China. Regarding to the Hoengyang (橫梁, cross-bar), we suggest that it was set up by double 5-feet supporting arms apart from the north tip of the Pyo in the radial direction. The 3:4:5 ratio in a rectangular triangle was used to place the Heongyang on the top of the Pyo at a distance of 4-feet (3-feet) in the vertical (horizontal) direction. We also discuss the structural problem when the Hoengyang is positioned apart from the top of the Pyo by supporting arms. In conclusion, we think that this study should be useful in restoring the Daegyupyo of the Joseon dynasty.

• Korean Journal of Food Science and Technology
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• v.19 no.3
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• pp.273-278
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• 1987

The physicochemical properties of dried oak mushrooms were investigated to determine the comparative effects of ethylene oxide (E.O) fumigation and gamma irradiation with doses at 1 and 5 kGy. The total amino acid content was relatively stable in irradiated groups in comparison with the control. Treatments with gamma irradiation did not effect the content of reducing sugar but caused en increase in free sugars, such as mannitol, arabitol and trehalose. There were no significant differences in concentrations of minerals. The amount of water and fat soluble pigments and the rancidity of the samples stored at $25^{\circ}C$ increased with increasing the storage time and the relative humidity, and the tendency to change was more apparent in E.O. fumigated sample than gamma irradiated one.

• Ocean and Polar Research
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• v.26 no.2
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• pp.133-143
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• 2004

For the purpose of understanding the cloud scattering effect of UV radiation at King Sejong station In West Antarctica, we analyzed the data measured by UV-Biometer at surface and compared its result with solar radiation model. The parameterization of UV radiation by cloud ice crystal was applied to solar radiation model and the sensitivity of this model for the variation of ice crystal was tested. The cloud optical thickness was calculated by using this solar radiation model. It was compared the result from calculation with CERES satellite data. In solar radiation model, the UV radiation was less scattered with increase of ice crystal size in cloud and this scattering effect was more important to UV-A radiation than Erythemal UV-B radiation. But scattering effects by altitude of cloud was not serious. The calculated cloud optical thicknesses in Erythemal UV-B and UV-A region were compared with CERES satellite data and the result by UV-A was more accurate than Erythemal UV-B region.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.493-504
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• 2004

The history books of East Asia about astronomical phenomena have the more records of the solar eclipse frequently than any other ones. It is because traditionally, the solar eclipse moaned the fate of dynasty and the king's rule. The Sun, the biggest thing in the heaven symbolized the king, and the solar eclipse foresaw that the king had the problem in private including the body, and the country might suffer from difficulties in a great scale. So the king and all of the ministers used to gather to hold a ceremony named Gusikrye(구식례) which solar eclipse may pass safely. Consequently, kings always had concernments on collecting informations of solar eclipse. Inspite of importance of solar eclipse predictions, but at the beginning of the Choseon, the predictions of the solar eclipse didn't fit. King Sejong compiled the Chiljeongsan-naepion (칠정산내편) and the Chiljeongsan-oepyeon(칠정산외편) to calculate the celestial phenomena including the solar eclipse. By the publications of these two books, the calendar making system of Choseon was firmly established. The Chiljeongsan-oepyeon adopted Huihui calendar(회회력) of Arabia. The Solar eclipse predictions of Chiljeongsan-oepyeon were relative correct compared to modern method in early Choseon dynasty.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.413-423
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• 2020

Over the wide area, King Sejong Station and the nearby land are uncovered with snow and ice conditions. Therefore, the active layer on the permafrost has been formed to be much thicker than the other Antarctica region. Electrical resistivity survey of Wenner and dipole-dipole arrays was undertaken at a series of time in the freezing season at the King Sejong Station to delineate subsurface structure and to monitor active layer in permafrost terrain. Time-lapse resistivity structures are well in terms of the vegetation distribution, ground surface temperature, and snow depth. Horizontal high resistivity belt(>1826 Ωm) at very shallow depth is thickening with the lapse of time, probably caused by the freezing of the water in the pore spaces with decrease of ground temperature. Subsurface structures for the area of low snow-cover and vegetated zone area are comprised of 0~0.5 m deep high-resistive gravel-rich soil, 0.5~3 m deep low-resistive active layer, and the underlying permafrost. In contrast, the unvegetated area and high snow-buildup is characterized with high resistivities larger than approximately 2000 Ωm due to freezing of the soil throughout the year. Data interpretation and correlation schemes explored in this paper can be applied to confirm the active layer, which is expected to get thinner in additional survey during the thawing season.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.3
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• pp.12-20
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• 2012

This study was carried out to investigate the backgrounds and spatial characteristics of the sericulture in the rear garden of the palace in Joseon Dynasty. Joseon Dynasty made the various efforts not only to enhance the promotion of agriculture but also sericulture since the main industry of Joseon Dynasty was farming. At the very beginning, Joseon Dynasty planted mulberry trees and built a silkworm-raising room(蠶室) around the Donggung(東宮). Then, King Sungjong(成宗) made Chaesangdan(採桑壇) in Changgyeong Palace and performed Chinzamryae(親蠶禮). The location of Chaesangdan varied as time goes on until the king Gwanghaegun(光海君). Lastly, King Yeongjo(英祖) made Chaesangdan and Junghaechinzambi(丁亥親蠶碑) in Gyeongbok Palace. Yeongjo(英祖) showed a strong attachment to Gyeongbok Palace and actively encouraged the sericulture. Chaesangdan was built in the east side of the palace which was appropriate for planting mulberry trees. Furthermore, a silkworm-raising room was located in this place at the era of King Sejong(世宗).

• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.29.4-30
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• 2010

A VHF meteor radar at King Sejong Station ($162.22^{\circ}S$, $58.78^{\circ}W$), Antarctica has been observing meteors during a period of March 2007-July 2009. We analyzed the height profiles of the observed meteor decay times between 70 and 95 km by classifying strong and weak meteors according to their estimated electron line densities. The height profiles of monthly averaged decay times show a peak whose altitude varies with season in the range of 80~85 km: higher peak in southern spring and summer than in fall and winter. The higher peak during summer is consistent with colder temperatures that cause faster chemical reactions of electron removal, as effective recombination rates measured by rocket experiments. The height profiles of 15-min averaged decay times show a clear increasing trend with decreasing altitude from 95 km to the peak altitude, especially for weak meteors. This feature for weak meteors is well explained by ambipolar diffusion of meteor trails, allowing one to estimate atmospheric temperatures and pressures, as in previous studies. However, the strong meteors show not only significant scatters but also different slope of the increasing trend from 95 km to the peak altitude. Therefore, atmospheric temperature estimation from meteor decay times should be applied for weak meteors only. In this study, we present the simple model decay times to explain the height profiles of the observed decay times and discuss the additional removal processes of meteor trail electrons through the empirical recombination and by icy particles.

• Atmosphere
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• v.21 no.4
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• pp.455-469
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• 2011

The Chugudae is a pedestal for the Chugugi. While many Chugudae were made during the Joseon Dynasty period, seven remained in existence until the early 20th century. Only five of them remain to this day-Gwansanggam (Royal Office of Astronomy and Meteorology), the Seonhwadang in Daegu, the Changdeok Palace, Tongyeong, and Yeongyeongdang. The Changdeok Palace Chugudae is the only existing model made not only as a meteorological instrument but also as a memorial statue. It has been a challenge to decipher 41 of the 368 characters in 'Chugugi-myeong (The title of the inscriptions on the Changdeok Palace Chugudae)' as these had been eroded. However, the interpretation of the full text of 'Chugugi-myeong' became possible thanks to the "Cheoljae Jinjeok (澈齋眞蹟)" which was discovered through this study. The key sentences of the 'Chugugi-myeong' include the reason for creation, the size and functions of the Chugugi and a eulogy to the reigns of King Sejong, Youngjo and Jeongjo. Moreover, its splendid design is worthy of further study. To conclude its true meaning and value, the Changdeok Palace Chugudae requires a more extensive investigation from the viewpoint of an art history.