• Korean Journal of Environment and Ecology
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• v.28 no.3
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• pp.281-286
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• 2014

This study was conducted to investigate the individual size and age of Kaloula borealis, a pair in amplexus. In June 2013, the total 23 pairs of Kaloula borealis were captured in the wetland located in Seongsan-eup and Daejeong-eup, Jeju Island. Size and age of each individual have been examined and as a result of analyzing SVL (snout-vent length), weight, length of forelimb and hindlimb of the collected 23 pairs, the females were shown to have the heavier weight and the longer SVL and hindlimb compared to males. No significant difference in the length of forelimb has been found between the female and the male. The average age of the male of the pair in amplexus was shown to be $5.17{\pm}0.26$, whereas the female was shown to be $6.22{\pm}0.28$, which indicates the higher average age in female compared to the male. The age range of Kaloula borealis was distributed from at least 3 years to 10 years at the maximum. A positive correlation was shown between age of the male and SVL; however, no significant difference was found in female. This study result expected to be utilized as an important base data in establishing the preservation and restoration strategy of endangered species, Kaloula borealis.

• Microbiology and Biotechnology Letters
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• v.41 no.4
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• pp.383-390
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• 2013

Several yeasts were isolated from flowers found in Gyonggi-do Province and Jeju island in Korea. They were then identified by a comparison of their PCR-amplified D1/D2 regions of 26S rDNA, internal transcribed spacer 1 and 2 inclusive of 5.8S rDNA, using the BLAST database. A total of fifty four yeast strains were isolated from wild flowers in Gyonggi-do and the genus Pseudozyma was noted as being dominant. A total of thirty two strains were isolated from Songaksan and Seongsan-ilchulbong in Jeju island and Sporobolomyces ruberrimus was seen to be dominant. The anti-gout xanthine oxidase inhibitory activities of the culture broths and cell-free extracts from eighty six yeast strains were then determined. The cell-free extracts of Pseudozyma hubeiensis 228-S-1 exhibited the highest xanthine oxidase inhibitory activity of 19.6%. The XOD inhibitor was also maximally produced when Pseudozyma hubeiensis 228-S-1 was cultured at $30^{\circ}C$ for 36h in YEPD medium.

• The Journal of Engineering Geology
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• v.33 no.1
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• pp.105-119
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• 2023

Water supply is decreasing due to climate change, and coastal and island regions are highly dependent on groundwater, reducing the amount of available water. For sustainable water supply in coastal and island regions, it is necessary to accurately diagnose the current condition and efficiently distribute and manage water. For a precise analysis of the groundwater flow in the coastal island region, submarine fresh groundwater discharge was calculated for the Seongsan basin in the eastern part of Jeju Island. Two methods were used to estimate the thickness of the fresh groundwater. One method employed vertical interpolation of measured electrical conductivity in a multi depth monitoring well; the other used theoretical Ghyben-Herzberg ratio. The value using the Ghyben-Herzberg ratio makes it impossible to accurately estimate the changing salt-saltwater interface, and the value analyzed by electrical conductivity can represent the current state of the freshwater-saltwater interface. Observed parameter was distributed on a virtual grid. The average of submarine fresh groundwater discharge fluxes for the virtual grid was determined as the watershed's representative flux. The submarine fresh groundwater discharge and flux distribution by year were also calculated at the basin scale. The method using electrical conductivity estimated the submarine fresh groundwater discharge from 2018 to 2020 to be 6.27 × 10⁶ m³/year; the method using the Ghyben-Herzberg ratio estimated a discharge of 10.87 × 10⁶ m³/year. The results presented in this study can be used as basis data for policies that determine sustainable water supply by using precise water budget analysis in coastal and island areas.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.35 no.4
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• pp.29-42
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• 2017

Jeongeuihyanggyo(旌義鄕校) is a kind of traditional, Confucian cultural landscapes that is located in Jeju special self-governing province. Its historical background illustrates that the first erection was started at Goseong-li of Seongsan-eup(城山邑 古城里) at Taejong(太宗) of 16 years(1417) and it moved to the west gate of Hyunseong(縣城) at Heojong(憲宗) of 15 years,(1849) Joseon. The aim at this study is to reveal characters of these Confucian Spatial Composition and Order, which are valuable resources that can be created into the cultural contents. The results demonstrate the characters of the Confucian cultural landscape as followings; the changing process of new building and its relocation, the utilization of antique maps in location interpretation of Jeongeuihyanggyo, Confucian symbolic elements of it, the spatial compositions and layouts of its buildings, physical structures, main buildings and their characters, locational points of topographic profile, changes of axial line at Daeseongjeon(大成殿), the D/H ratio of its courts. This study can show that Jeongeuihyanggyo is a case for realizing the Confucian reformation to enhance Seongeup Hyun's education standard considering the locality of the site which is an isolated island like Jejudo(濟州島). The author can see that the example of Confucian space is applied to various layout techniques, both horizontally and vertically, in a limited space condition of being in the castle. Therefore, it is necessary to revive this point so that it can utilize unique Confucian cultural landscape possessed only by Jeongeuihyanggyo.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.199-205
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• 2008

This study was carried out to find out causes of high Ni content and characteristics of potential increase of Cu and Zn contents in the soils of Jeju area. Soil samples were collected from 4 series of Alfisols, 35 series of Andisols, 9 series of Entisols, 16 series of Inceptisols, and 1 series of Ultisols, respectively. Parent material (gravel) samples were also collected from the same sites where soil samples were taken. Both soil and parent material samples were analyzed for Ni, Cu, and Zn. The average Ni content of all the soil samples was $79.2mg\;kg^{-1}$, which was exceeded warning standard for Ni against the Soil Conservation Act in Korea, whereas that of Cu and Zn contents were lower than the warning standard for Cu and Zn. The difference of Ni, Cu and Zn content was not consistent depending upon soil color. Ni content in the soil samples from Entisols was particularly high, whereas that from the other soil orders was similar to each other. Cu and Zn contents in the soil samples were similar regardless of the difference in soil order. Ni content in Seongsan Formation(SSF), Cinder cone(C) and acicular Feldspar Olivine Basalt(FOB) was high, while that in Feldspar Basalt(FB) and Trachy Andesite lava(TA) was low. Ni content in the non-agricultural land was higher compared with that in the agricultural land, whereas Cu and Zn contents in the non-agricultural land were significantly lower than that of agricultural land. The topsoil/subsoil ratios for Ni content in most of the soil samples were less than 1, while that for total contents of Cu and Zn in many of the soil samples were larger than 1 indicating potential Cu and Zn accumulation in topsoil by artificial reasons.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.35-43
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• 2021

Citrus quality is generally determined by its sugar content and acidity. In particular, sugar content is a very important factor because it determines the taste of citrus. Currently, the most commonly used method of measuring citrus sugar content in farms is a portable juiced sugar meter and a non-destructive sugar meter. This method can be easily measured by individuals, but the accuracy of the sugar content is inferior to that of the citrus NongHyup official machine. In particular, there is an error difference of 0.5 Brix or more, which is still insufficient for use in the field. Therefore, in this paper, we propose an AI model that predicts the citrus sugar content of unmeasured days within the error range of 0.5 Brix or less based on the previously collected citrus sugar content and meteorological data (average temperature, humidity, rainfall, solar radiation, and average wind speed). In addition, it was confirmed that the prediction model proposed through performance evaluation had an mean absolute error of 0.1154 for Seongsan area and 0.1983 for the Hawon area in Jeju Island. Lastly, the proposed model supports an error difference of less than 0.5 Brix and is a technology that supports predictive measurement, so it is expected that its usability will be highly progressive.