• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.356-362
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• 2007

The rhizobacterial diversity associated with 9 native plant species inhabiting coastal sand dunes in Tae-an area, Chungnam Province, was studied using the denaturing gradient gel electrophoresis (DGGE) fingerprinting analysis over three times from October 2003 to March 2004. One dominant band commonly occurred in all of the rhizosphere samples, which was identified as that of Lysobacter enzymogenes. The other common bands included those derived from species of Pseudomonas and Bacillus. It was notable that L. enzymogenes was dominant in all of the 9 plant species and such dominance was consistent throughout the whole sampling period, which confirms the previous study by Lee et al. (2006a). The Bacillus bands were detected in all of the three samplings, and those of Pseudomonas were notable in the samples of December 2003. By the DGGE analysis alone, the significance of Lysobacter to the sand dune plants is not clear. However, considering their presence in healthy plants and the dominance in all plant species, Lysobacter may have positive roles in the survival or growth of the plants in sand dune area.

• Microbiology and Biotechnology Letters
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• v.40 no.3
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• pp.261-267
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• 2012

Coastal sand dunes are important for ecosystems due to the variety of rare species that can be found in this kind of habitat, and the beautiful landscapes they create. For environmental remediation, a potential strategy is phytoremediation using the symbiotic relationship of plants and microbes in the rhizosphere, which has proven ecologically sound, safe, and cost effective. Ninety-five colonies were isolated from the rhizosphere soil (RS) or rhizoplane (RP) of Rorippa islandica, Rumex crispus, Artemisia princeps var. orientalis, Lilium sp Stellaria media, and Gramineae. These colonies were then tested for plant growth promoting activities (PGPAs) such as 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, and siderphores synthesis ability. In addition, salt tolerance was evaluated at 4% and 8% salt concentrations. It was observed that amongst the test subjects about 50% of the strains had a high resistance to salinity. Many of them could produce indole-3-acetic acid (IAA) IAA (in RS 13.9% and in RP 7.6%), exhibited ACC deaminase activity (55.8% in RS and 36.6% in RP), and could synthesize siderphores (62.7% in RS and 50% in RP). Correlation coefficient analyses were carried out for the three kinds of plant growth promoting abilities (PGPA) and salt tolerance. A positive correlation was found between an ability to synthesize siderphores and ACC deaminase activity (r=0.605, p<0.037). Similarly, positive correlations were noted between salt tolerance and ACC deaminase activity (r=0.762, p<0.004, r=0.771), and salt tolerance and an ability to synthesize siderphores (r=0.771, p<0.003).

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.1
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• pp.18-30
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• 2017

The East Sea is almost entirely composed of sandy facies, and the facies type is the major factor influencing benthic polychaete communities. There have been few studies of the effects of environmental factors on benthic polychaetes in thermal discharge areas consisting of different sediment types. This study identified the spatial distribution patterns based on the species composition and distribution of benthic polychaete communities, and the environmental factors influencing benthic polychaetes near power plants were investigated. The polychaete communities in the Uljin, Hupo, and Gori coastal areas near the power plants in the East Sea were seasonally investigated from August 2006 to February 2013. As a result, 283 species were collected. The dominant species were Spiophanes bombyx, Magelona japonica, Lumbrineris longifolia, and Sternaspis scutata. Spiophanes bombyx was the dominant species at Uljin and Hupo, but M. japonica was the dominant species at Gori. Two dominant species from the coastal waters of the East Sea, Lumbrineris longifolia and M. japonica, were rare in the power plant water intake or drainage areas. Cluster analysis was performed to divide the study area into groups by the total organic carbon content, sediment grain size and facies patterns. This study suggests that the community structures of polychaetes are more affected by the total organic carbon, grain size of sediment and facies than by disturbance from thermal discharge, which only affected the polychaete community near power plant drainage areas.

• Journal of Ecology and Environment
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• v.42 no.3
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• pp.120-127
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• 2018

Background: Cakile edentula (Bigelow) Hook. is a successful invader that has been propagating globally. In Korea, Cakile edentula was found in 2008 for the first time, in the east coast of Korean peninsula. Based on site surveys conducted thereafter, Cakile edentula has propagated in the east coast from Goseong to Jeongdongjin, Gangneung and in the west coast of city of Hwaseong of Gyeonggi-do Province, and Taeangun County of Chungcheongnam-do Province. Results: Cakile edentula has infiltrated into four different vegetation communities (syntaxa) (Calystegio soldanellaeSalsoletum komarovii Ohba, Miyawakiet Tx.1967; Elymo-caricetum Kobomugi Miyawaki 1967; Carex pumila; and Calystegia soldanella) belonging to phytosociological classes of saltwort (barilla) and coastal glehnia. Cakile edentula competes with dominant species such as the saltwort (barilla) and beach morning glory, causing qualitative changes in species composition. It also affects local ecosystems through its competition with indigenous species, causing destruction of the traditional landscape. Conclusions: However, competition of Cakile edentula with indigenous species and the resulting replacement of such species are limitedly reported. Potential competitors with Cakile edentula have not been found yet. In Northeast Asia, qualitative changes realized in local ecosystems due to invasion of Cakile edentula are significantly noticeable. These necessitate proper controls for this invasive alien species to protect and preserve coastal dune areas.

• Ocean and Polar Research
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• v.33 no.4
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• pp.421-434
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• 2011

Although thermal effluent from coastal power plants affects marine ecosystems, few studies have examined the spatiotemporal distribution of macrobenthic communities in a coastal area of Korea with thermal discharge. This study analyzed the species composition and abundance of a macrobenthic community in relation to environmental variables for a period of 1 year. In total 334 macrobenthic faunal species were collected; the mean density was 3,221 ind/$m^2$. The number of species and the density of macrobenthic fauna increased with distance from the thermal discharge site. Cluster analysis indicated that the macrobenthic community could be divided into two groups: group I in shallow (< 30 m deep) and group II in the outer areas (> 30 m deep). Group I showed the lowest species density and diversity. Four polychaetes, including Magelona japonica, Spiophanes bombyx, Scolotoma longifolia and Chaetozone setosa, all of which have been dominant species since 1987, exhibited higher mean densities in the area distant from the thermal discharge (the outer and north areas). Conversely, the warm-adapted and opportunistic species, such as the amphipods Urothoe convexa and Mandibulophoxus mai, the bivalve Felaniella sowerbyi, and the polychaete Rhynchospio sp., were more abundant in the thermal discharge region. The results of this study indicate that thermal effluent influences macrobenthic communities in the shallow area, while other environmental variables, such as depth, sediment grain size, and TOC, are more important determinants of the macrobenthic communities in deeper regions (> 30 m deep).

• The Korean Journal of Ecology
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• v.26 no.3
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• pp.103-108
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• 2003

This study examined the coastal sand dune vegetation before and after the construction of an embankment on Anmado Island in order to compare vegetation in relation to the development of islands. A total of 24 species distributed on the sand dunes. 18 species were found to be in common before and after the construction of the embankment, which included Vitex rotundifolia, Imperata cylindrica var. koenigii, Zoysia sinica, etc. The species which were not found in this survey included Rumex japonicus, Setaria viridis, Portulaca oleracea, Artemisia japonica, Poiygonum aviculare, etc, and new species included Arena fatua, Carex boottiana, Lycium chinense, Leonurus sibiricus, Torilis japonica, Solanum carolinense, etc. The washing away of sand brought about the changes in habitat and the increase in naturalized plants, which included Oenothera odorata, Lepidium apetalum, Bidens bipinnata, Erigeron canadensis, Datura stramonium, Xanthium strumarium, Arena fatua, Solanum carolinense etc. In addition, the disturbance to this habitat led to the changes in vegetation. The main plant communities in the surveyed site were classified as Vitex rotundifolia-Imperata cylindrica var. koenigil community, Zoysia sinica-Calystegia soldanella community and Messerschmidia sibirica community. The sand dune vegetation on Anmado Island changed with regard to the community and the composition of species after the construction of the embankment, due to the sand being severely eroded. While Vitex rotundifolia community and Commelina communis community were found before the construction of the embankment, they were replaced by Vitex rotundifolia-Imperata cylindrica var. koenigii community, Zoysia sinica-Calystegia soldanella community and Messerschmidia sibirica community, after the construction of the embankment.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.268-275
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• 2008

In order to develop the multi-functional rhizobacteria that can exert positive effect on the growth of plants growing in the coastal sand dune located along East Coast of Korea, rhizospheral bacteria of 11 different plants from this area were isolated 1,330 rhizobacteria. Among these, 23 strains were able to produce auxin and had spectrum of antagonism toward various phytopathogenic microbes. To know the mechanism of this antifungal activity, these 23 strains were subjected to further analyses; 19 strains of these produced siderophore as determined by color reaction on CAS-blue plate, 4 strains produced antifungal cellulase as judged by color change on CMC-Congo red plate, 17 strains were able to utilized insoluble phosphate salts, also determined by clear zone formation on PVK medium. Identification of the strain was assigned to all 23 strains by l6s rDNA sequence analysed, and all were identified to be in the genus of Bacillus and Pseudomonas. One strain of these, denoted Pseudomonas fluorescens IB4-14, showed ACC deaminase activity which is known to be involved in the resistance of environmental stress such as salt and drought. Also, P. fluorescens IB4-l4 showed the germination stimulation and roots growth promoting activity on the in vivo assay of Lysimachia mauritiana Lam. (spoonleaf yellow loosestrife).

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11a
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• pp.321-331
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• 2005

Recently. three-dimensional models have been used for aquatic dispersion of radioactive effluents in relation to nuclear power plant siting based on the Notice No. 2003-12 'Guideline for investigating and assessing hydrological and aquatic characteristics of nuclear facility site' of the Ministry of Science and Technology (MOST) in Korea. Several nuclear power plants have been under construction or planed. which are Shin-Korl Unit 1 and 2, Shin-Wolsong Unit 1 and 2, and Shln-Ulchin Unit 1 and 2. For assessing the aquatic dispersion of radionuclides released from the above nuclear power plants, it is necessary to know the coastal currents around sites which are affected by circulation of East Sea. In this study, a three dimensional hydrodynamic model for the circulation of the East Sea of Korea has been developed as the first Phase, which Is based on the RIAMOM. The model uses the primitive equation with hydrostatic approximation, and uses Arakawa-B grid system horizontally and Z-coordinate vertically. Model domain is $126.5^{\circ}E\;to\;142.5^{\circ}E$ of east longitude and $33^{\circ}N\;and\;52^{\circ}N$ of the north latitude. The space of the horizontal grid was $1/12^{\circ}$ to longitude and latitude direction and vortical level was divided to 20. This model uses Generalized Arakawa Scheme. Slant Advection, and Mode-Splitting Method. The input data were from JODC, KNFRDI, and ECMWF. The model ing results are in fairly good agreement with schematic patterns of the surface circulation in the East Sea The local current model and aquatic dispersion model of the coastal region will be developed as the second phase. The oceanic dispersion experiments will be also tarried out by using ARGO Drifter around a nuclear pelter plant site.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.20 no.5
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• pp.452-460
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• 2008

Anti-foaming agents and foam fences have been used to remove the foam at the outfall of power plants, but there are some problems as consumption of maintenance costs and insufficiency of effect. Therefore, development of the methods how to remove the foam by stable coastal structure has been required. In this study, numerical simulation of air entrainment was carried out to design the submerged outlet structure for reducing foam using curtain walls. The air entrainment rate and the discharge of entrained air change according to the shape of weir and curtain wall. Hence, it is necessary to design the optimum section through comparison of each case. The optimum section which has the maximum rate of foam reduction was determined by the simulation results. In addition, it was found that the flow velocity at the submerged outlet is to be smaller than 1 m/s and the submerged depth of curtain wall is to be taller than height of the submerged outlet section.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.200-201
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• 2023

Digital twin technology is used in various fields as a method of creating a virtual world to minimize the cost of solving problems in the real world, and is also actively used in the maritime field, such as large-scale systems such as ships and offshore plants. In this paper, we tried to build a digital twin of coastal waters using a ship-handling simulator. The digital twin of the coastal waters developed in this way can be used to safely manage Korea's coastal waters, where maritime traffic is complicated, by providing a actual maritime traffic data. It can be usefully used to develop and advance technologies related to maritime autonomous surface ships and intelligent maritime traffic information services in coastal waters. In addition, it can be used as a 3D-based monitoring equipment for areas where physical monitoring is difficult but real-time maritime traffic monitoring is necessary, and can provide functions to safely manage maritime traffic situations such as aerial views of ports/control areas, bridge views/blind sector views of ships in operation.