• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.5
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• pp.733-741
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• 2021

Jeju island is the largest island of South Korea, and has a relatively warm climate due to its geographical characteristics. These features have fostered development of various fermented foods distinct to Jeju island. Therefore, the functional activity of the lactic acid bacteria (LAB) isolated from the Jeju region's traditional fermented foods, including Kimchi and Jeotgal was characterized in this study. Fifteen strains were isolated from 6 types of fermented food. These strains include Enterococcus spp., Lactoplantibacillus spp., and Weisella spp. Several experiments were carried out to assess functional characteristics including acid resistance, bile resistance, hemolysis, DPPH and ABTS radical scavenging activity, and cholesterol-lowering activity. Three isolated strains (J-4, J-6 and J-10) exhibited high acid resistance, while the other 3 isolates (J-1, J-4 and J-6) showed high bile salt resistance. The strains displayed varied DPPH and ABTS radical scavenging activity: 71.14-86.42% among the first 3 strains, and 50.11-75.11% among the remaining 3 strains. Cholesterol-lowering activities were in the range 15.74-82.90% for all isolated strains. In conclusion, these studies suggest that isolated LAB strains from Jeju island traditional fermented foods possess the potential for broader application in the food industry.

• Maritime Security
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• v.8 no.1
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• pp.73-102
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• 2024

The recent rise of China has the potential to intensify competition for hegemony between the U.S. and China. China is strengthening its influence in the region through maritime military actions represented by Anti-Access/Area Denial(A2/AD). The U.S. is establishing a new concept of operation to respond to China's A2/AD and achieve superiority in the U.S - China competition. In particular, this study focused on the U.S. Marine Corps' contribution to naval operations as a means of sea denial through Expeditionary Advanced Base Operation(EABO), which mainly centered on islands, and changes to strengthen its influence in the sea. By applying these changes in the U.S. Marine Corps to the ROK Marine Corps, the future direction of the ROK Marine Corps' offensive island area operations that can contribute to joint and naval operations was suggested. This study is meaningful in that it presents the ROK Marine Corps' offensive island area operations using the strategic value of the island from the perspective of sea denial. However, by presenting the direction of operational performance and military power construction / development conceptually, specific discussions of this aspect are needed in the future. I hope that this study will be the starting point.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.4 no.1
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• pp.1-10
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• 2008

A magnetotelluric survey and geological survey have been performed to delineate deeply extended fracture systems at the geothermal field in Seokmo Island, Inchon, Korea. One borehole(BH-1) succeed to meet a large fracture system at the depth of 750 m where approximately $72^{\circ}C$ geothermal water is overflowing, while the other borehole(BH-2), which is about 200 m eastward from BH-1, failed to develop enough geothermal water even at the depth of 1,200m. Though there have been so many electric noise sources around the survey region, good quality of MT data above 1 Hz could be obtained with careful installation, remote reference processing. Inversion of MT data for two lines roughly perpendicular to the two major lineaments respectively show that the two lineaments are related to the fracture systems that are extended at least down to 1.5 km depth and inclined eastwards. From the interpretation, additional drilling for BH-2 is recommended and finally meet the fracture systems at the depth of 1,280 m and resulted in overflow of large amount of geothermal water of temperature $69.4^{\circ}C$ from BH-2.

• Journal of Soil and Groundwater Environment
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• v.25 no.1
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• pp.84-94
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• 2020

Jeju Island is seeking reliable ways to secure alternative water resources using rainwater in order to conserve and manage its groundwater as sustainable water resources. The purpose of this study is to investigate the rainwater storage capability of small-size storage facilities installed at farmhouses in Uigwi and Wimi of Namwon-eup region. The rainwater outflows from the storage facilities in rain events were analyzed. The appropriate size of rainwater utilizing facilities are suggested to be about 5,800 ㎥ in Uigwi area and 4,900 ㎥ in Wimi area based on the calculation from the rainfall frequency and runoff amounts. If those facilities are put into operation in Uigwi and Wimi area, it is estimated approximately 32.3 and 11.5% of total agricultural water can be supplied by the facilities. Wimi area showed low rainwater usage because of less number of facilities relative to the size of farm areas and less intensive underground water usage. It is analyzed that more than 55% of agricultural water can be supplied by rainwater if 70 facilities without the rainwater facilities are connected to the rainwater utilizing facilities.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.1
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• pp.39-48
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• 2013

The solar radiation is the primary energy source that drives many of the earth's physical and biological processes and climate change. Understanding its importance to the solar radiation observation is a key to understanding a broad range of natural processes, agricultural, energy and human activities. The purpose of this study is to estimate solar radiation using sunshine duration, and to estimate distribution of solar radiation using a topography factor considering surface slope and aspect in complex terrain. The result of regression analysis between ratio of solar radiation and sunshine duration from 2001 to 2010 shows high $R^2$ value of 0.878. Regression analyses indicated that topographic attributes including elevation, slope and aspect had significant effects on solar radiation. The variation of topographic factor with aspect and slope for the summer and winter are considered. The highest month of daily mean solar radiation at Jeju island appears in April of 20.61 $MJ{\cdot}m^{-2}{\cdot}day^{-1}$, and the lowest month appears in December of 6.90 $MJ{\cdot}m^{-2}{\cdot}day^{-1}$. These results provided useful quantitative information about the influence of topography on solar radiation in the island region.

• Korean Journal of Ichthyology
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• v.27 no.3
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• pp.243-248
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• 2015

Based on three scorpionfish specimens (131.8~163.4 mm SL) collected from the coastal waters of Jeju Island, we described Scorpaenopsis neglecta as the first record from Korea. They were characterized by having 12 dorsal fin spines, lacking of palatal teeth and of black pigment between the first and third dorsal fin spines, wider interorbital region than orbital diameter, no median interorbital ridge, uppermost opercular spine with multicusps, and a broad blackish band distally and numerous various sized black spots on inner side of pectoral fin. We proposed a new Korean name, "Ssol-chi-u-reug" for the species.

• Journal of the Korean Solar Energy Society
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• v.28 no.1
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• pp.83-89
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• 2008

This paper presents the characteristics of lightning pver Jeju island and a case of emergency stop of a wind turbine due to lightning. Using the IMPACT ESP sensor to detect lightning, the data on lightning frequency, lightning strength, regional lightning event were obtained and analyzed in detail. The measurement period was for 3 years from 2004 to 2006. As a result, lightning occulted the most frequently in July and August. As for lightning strength, lightning with grades -4 to -6 and +3 to +5 occur ed more frequently. The eastern part of Jeju island had much more lightning frequency compared with the western part of it. Lightning with high grade occurred mainly in offshore site and the coastal region. Furthermore, the data on wind turbine stop caused by lightning was analyzed. Although wind turbine lightning damage was not much in this study, the investigation on lightning damage or lightning faults to a wind turbine should be conducted in Korea to increase availability of wind turbine.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.1112-1118
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• 2014

In island and backcountry areas, electrical power is usually supplied by diesel generators. It is difficult for small scale diesel generators to have an economy of scale owing to the usage of fossil fuels to produce electricity. Also, there is a problem of carbon dioxide emissions that brings some environmental pollution to the entire region of the area. For solving those, this paper proposes a design method of autonomous micro-grid to minimize the fossil fuels of diesel generator, which is composed of diesel generator, wind turbine, battery energy storage system and photovoltaic generation system. The proposed method was verified through computer simulation and micro-grid operation system.

• Korean Journal of Ichthyology
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• v.34 no.1
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• pp.64-70
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• 2022

The Eyebar goby, Gnatholepis cauerensis is reported firstly from Korea, based on four specimens (36.3~47.1 mm in SL) collected at depth range of 12~16 m in the southern coastal waters of Jejudo Island, Korea. They are characterized by having mostly ctenoid scales on body, head including cheek, opercle, and middle of predorsal region with cycloid scales, and a unique coloration of yellow blotch with marginally black marking above pectoral fin base as well as transverse black bar below eye. A new Korean name, "Geom-eun-nun-ddi-mang-dug", is proposed for the species.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.2
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• pp.69-71
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• 2023

The Korean field mouse, Apodemus peninsulae mitochondrial genome has previously been reported for mice obtained from mainland Korea and China. In this investigation the complete mitochondrial genome sequence for a mouse obtained from Baengnyeong Island (BI) in South Korea was determined using high-throughput whole-genome sequencing for the first time. The circular genome was determined to be 16,268 bp in length. It was found to be composed of a typical complement gene that encodes 13 protein subunits of enzymes involved in oxidative phosphorylation, two ribosomal RNAs, 22 transfer RNAs, and one control region. Phylogenetic analysis involved 13 amino acid sequences and demonstrated that the A. peninsulae genome from BI was more closely grouped with two Korean samples (HQ660074 and JN546584) than the Chinese (KP671850) sample. This study verified the evolutionary status of A. peninsulae inhabiting the BI at the molecular level, and could be a significant supplement to the genetic background.