• Maritime Security
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• v.1 no.1
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• pp.149-173
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• 2020

While the United States and other Western states are in trouble with COVID-19 crisis, China is continuing its aggressive ocean expansion with its Gray-zone strategy. The Gray-zone strategy, which China uses around the South China Sea, refers to a strategy that promotes a change in international politics by creating an unclear state, neither war or peace. China, which is trying to expand its influence across East Asia, will also try to project a Gray zone strategy on the Korean Peninsula. The possible scenarios are as follows: 1) South Korea is accidentally involved in a dispute in the South China Sea, 2) Military conflicts between South Korea and China is caused by illegal fishing of Chinese boats in Yellow Sea, 3) China tries to interfere with Socotra Rock, 4) Unlikely, but possible in the future that China induce the military conflicts between Korea and Japan on the Dokdo issue. In order to cope with these scenarios, Korea should prepare the following measures from a long-term perspective: the creation of an Asian maritime safety fleet, the integ rated operation of the navy and the coast guard in the framework of the national fleet, and strengthening the conflict control system for China's provocations.

• Journal of The Korean Association of Information Education
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• v.26 no.3
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• pp.153-165
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• 2022

This study is about the Novel Engineering(NE) education program : a class model that combines reading and engineering. By including the process of directly designing and programming a virtual reality using CospacesEdu (a VR authoring tool for the NE class), the effects of the educational program on learners' STEAM literacy and Learning immersion are demonstrated. Moreover, the subject of this education is Dokdo in South Korea. As a result, the average of STEAM literacy is increased, and a significant change is confirmed statistically in Convergence. Learning immersion shows significant improvement in Challenges-skills balance. On the other hand, some students experience difficulties due to the long research stages, from reading a book to researching for information to designing VR and rewriting a story with the collected information. In conclusion, this study will help generalise other education using NE, and this developed program will be a reference that would suggest a new way of teaching.

• Ocean and Polar Research
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• v.24 no.4
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• pp.429-442
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• 2002

The faunal assembalges of macrobenthos and their habitat conditions on the soft-bottoms around Dokdo(Dok Island) was investigated using a box corer and a van Veen grab in Sept. 1999 and May 2000. The sediments in the slope sites were composed of sand particles and those in Ullneung Basin were mud. The sediments in the shelf sites were in the range of fine to medium sand. The organic content of the slope sediments was in the range of 1 to 2%. The macrobenthos occurred at the slope sites represented by 15faunal groups belonging to 8 phyla, and the major faunal group was polychaetous annelids. They comprised ca. 80.6% in slope sites, and 84.8% in shelf sites. Dominant species in the slope were Exogone verugera(40.9%), Cossura longocirrata (8.4%), Tharyx sp. (6.6%), Scalibregma inflatum (4.9%), Aedicira sp. (4.7%), Aricidea ramosa (3.8%), and Sigambra tentaculata (3.7%). Dominant species in the shelf were Chone sp. (49.3%), Tharyx sp. (18.4%), Ophelina acuminata (6.7%), Chaetozone setosa (3.8%), Glycera sp. (2.6%), and Aedicira sp. (2.4%). The mean densities of macrobenthos in the slope and shelf area were $2,028\;ind./m^2$ and $456\;ind./m^2$, respectively. The trophic composition of benthic polychaete worms in the slope area was different from that in shallow shelf area: surface deposit feeding worms were most abundant in slope area whereas filter feeding worms in shelf area. According to the cluster analysis and MDS plots, the spatial distribution of macrobenthos in Dokdo slope region was related with the sediment properties such as particle size and organic content. In the case of vertical distribution of macrobenthos in slope sites, most faunas concentrated in the upper sediment layer within 2cm depth.

• Economic and Environmental Geology
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• v.43 no.6
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• pp.625-636
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• 2010

The geophysical characteristics and geological structure of the northeastern part of the Ulleung Basin were investigated from interpretation of geophysical data including gravity, magnetic, bathymetry data, and seismic data. Relative correction was applied to reduce errors between sets of gravity and magnetic data, obtained at different times and by different equipments. The northeastern margin of the Ulleung Basin is characterized by complicated morphology consisting of volcanic islands (Ulleungdo and Dokdo), the Dokdo seamounts, and a deep pathway (Korea Gap) with the maximum depth of -2500 m. Free-air anomalies generally reflect the topography effect. There are high anomalies over the volcanic islands and the Dokdo seamounts. Except local anomalous zones of volcanic edifices, the gradual increasing of the Bouguer anomalies from the Oki Bank toward the Ulleung Basin and the Korea Gap is related to higher mantle level and denser crust in the central of the Ulleung Basin. Complicated magnetic anomalies in the study area occur over volcanic islands and seamounts. The power spectrum analysis of the Bouguer anomalies indicates that the depth to the averaged Moho discontinuity is -16.1 km. The inversion of the Bouguer anomaly shows that the Moho depth under the Korea Gap is about -16~17 km and the Moho depths towards the Oki Bank and the northwestern part of Ulleung Island are gradually deeper. The inversion result suggests that the crust of the Ulleung Basin is thicker than normal oceanic crusts. The result of 20 gravity modeling is in good agreement with the results of the power spectrum analysis and the inversion of the Bouguer anomaly. Except the volcanic edifices, the main pattern of magnetization distribution shows lineation in NE-SW. The inversion results, the 2D gravity modeling, and the magnetization distribution support possible NE-SW spreading of the Ulleung Basin proposed by other papers.

• Korean Journal of Heritage: History & Science
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• v.42 no.1
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• pp.72-87
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• 2009

This research is insect diversity analysis on the basis of survey results and bibliographies of Hongdo Island, Mts. Seoraksan, Hallasan, Daeamsan & Daeusan, Hyangnobong peak & Geonbongsan nature reserves and Dokdo Protected Natural Area among 10 designated nature reserves. The Mt. Hallasan nature reserve has 1,867 species in 22 orders and shows the highest species diversity. The species diversities of Mt. Seoraksan, Mt. Hyangnobong peak & Geonbongsan, Hongdo Island, Mt. Daeamsan & Daeusan, and Dokdo Protected Natural Area reveal 1,604 species in 19 orders, 704 species in 18 orders, 474 species in 19 orders, 468 species in 16 orders, and 114 species in 11 orders, respectively, in descending order. The order Lepidoptera shows as dominant taxa in Hongdo, Seoraksan, Hallasan, Hyangnobong peak & Geonbongsan, whereas the order Coleoptera as subdominant taxa in these areas. On the other hand, in Mt. Daeamsan & Daeusan, and Dokdo Protected Natural Area, the order Coleoptera appears as dominant taxa whereas the order Lepidoptera as subdominant taxa. The order Ephemeroptera has been shown the highest species diversity in Seoraksan which is reported to 25 species, Odonata in Hallasan to 28, Dermaptera in Seoraksan to 9, Orthoptera in Hallasan to 51, Hemiptera in Hallasan to 175, Homoptera in Seoraksan to 126, Hymenoptera in Hallasan to 183, and Diptera in Hallasan to 206. The species diversity is generally poor in Daeamsan & Daeusan, Hyangnobong peak & Geonbongsan, and Dokdo Protected Natural Area. Maybe this result is caused by the lack of various academic surveys compared to the other areas. It is needed to study systematic academic investigation on insect in the nature reserve areas in Korea, and to plan appropriate management and conservation on natural environment considering biodiversity of each nature reserve area.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.2
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• pp.351-373
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• 2019

The cold eddies around the Ulleung Basin in the East Sea were identified from satellite altimeter sea level data using the Winding-Angle method from 1993 to 2015. Among the cold eddies, the Dokdo Cold Eddies (DCEs), which were formed at the first meandering trough of the East Korea Warm Current (EKWC) and were pinched off to the southwest from the eastward flow, were classified and their migration patterns were analyzed. The vertical structures of water temperature, salinity, and flow velocity near the DCE center were also examined using numerical simulation and observation data provided by the Hybrid Coordinate Ocean Model and the National Institute of Fisheries Science, respectively. A total of 112 DCEs were generated for 23 years. Of these, 39 DCEs migrated westward and arrived off the east coast of Korea. The average travel distance was 250.9 km, the average lifespan was 93 days, and the average travel speed was 3.5 cm/s. The other 73 DCEs had moved to the east or had hovered around the generated location until they disappeared. At 50-100 m depth under the DCE, water temperature and salinity (T < $5^{\circ}C$, S < 34.1) were lower than those of ambient water and isotherms made a dome shape. Current faster than 10 cm/s circulates counterclockwise from the surface to 300 m depth at 38 km away from the center of DCE. After the EKWC separates from the coast, it flows eastward and starts to meander near Ulleungdo. The first trough of the meander in the east of Ulleungdo is pushed deep into the southwest and forms a cold eddy (DCE), which is shed from the meander in the south of Ulleungdo. While a DCE moves westward, it circumvents the Ulleung Warm Eddy (UWE) clockwise and follows U shape path toward the east coast of Korea. When the DCE arrives near the coast, the EKWC separates from the coast at the south of DCE and circumvents the DCE. As the DCE near the coast weakens and extinguishes about 30 days later after the arrival, the EKWC flows northward along the coast recovering its original path. The DCE steadily transports heat and salt from the north to the south, which helps to form a cold water region in the southwest of the Ulleung Basin and brings positive vorticity to change the separation latitude and path of the EKWC. Some of the DCEs moving to the west were merged into a coastal cold eddy to form a wide cold water region in the west of Ulleung Basin and to create a elongated anticlockwise circulation, which separated the UWE in the north from the EKWC in the south.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.299-306
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• 2009

Fish fauna in the eastern Yellow Sea was determined using samples collected by an otter trawl from September 1999 to November 2001. The fish consisted of 97 species belonging to 80 genera and 50 families. The major taxa were the Perciformes (40 spp.), Pleuronectiformes (17 spp.), Scorpaeniformes (11 spp.) and Clupeiformes (10 spp.). Larimichthys polyactis, Engraulis japonicus, Liparis tanakai, Pampus echinogaster, Lophius lituron and Collichthys niveatus were predominated in abundance in the study area. The composition of the fish fauna has changed during the last three decades.

• Korean Journal of Environmental Biology
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• v.33 no.2
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• pp.170-176
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• 2015

Oncholaimid nematode, Oncholaimus secundicollis Shimada, Kajihara and Mawatari, 2009, is firstly reported based on a comparative morphological study. The present specimens of O. secundicollis are collected from rocky intertidal seagrass on the eastern coast of Korea. Oncholaimus secundicollis is distinguished from all of its congeners by the following combination of morphological characteristics: buccal cavity large with thick cuticular wall and three teeth, left subventral tooth larger than right subventral or dorsal teeth, and the presence of two remarkable precloacal papillae with nine pairs of cloacal setae and single ventral tail papilla with two pairs of short setae. In this study, we provide taxonomic description and illustration of unrecorded species of the genus Oncholaimus.

• Animal Systematics, Evolution and Diversity
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• v.29 no.2
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• pp.152-159
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• 2013

As a result of continuous taxonomic studies on the Korean crabs, two varunid crabs, Hemigrapsus takanoi Asakura and Watanabe, 2005 and Sestrostoma toriumii (Takeda, 1974), are newly reported from Korean waters. Hemigrapsus takanoi, as a sibling species of H. penicillatus, has not been recognized in Korean waters, and this species occurs in the sympatric habitat with H. penicillatus in the Korean peninsula. Sestrostoma toriumii (Takeda, 1974) is associated with thallassinid Upogebia major (De Haan, 1841) and echiuran Urechis unicintus (Von Drache, 1881) as the case of S. balssi (Shen, 1932). The Korean S. toriumii showed smaller size than those mentioned in the original description. Their illustrations and pictures are provided with descriptions, and the distributions of these species in the Korean peninsula are also provided.

• The Korean Journal of Malacology
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• v.26 no.2
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• pp.171-175
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• 2010

Korean cephalopods only recorded with Korean name in the literature were reviewed to solve confusions in use of their Korean name for taxonomic studies of cephalopods in Korea, and to prepare a basic check list for standardizing total cephaolopods fauna of Korea in the future. A total 38 cephalopods species with Korean names were listed in this study; 14 species in order Sepioidea, 17 species in Teuthoidea, 7 species in Octopoda. The etymology and some problems of Korean names of cephalopods occurring in Korea, and the useable rules for naming cephalopods with Korean words are recommended and discussed.