• Journal of Ocean Engineering and Technology
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• v.27 no.6
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• pp.16-21
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• 2013

In this paper, the mooring system for a floating wave energy farm is designed based on a two-dimensional analysis. The mooring system uses an anchorless mooring line linking two floaters in a floating wave energy farm. The basic equation to determine the length of the mooring line between the two floaters is proposed. The other properties such as the diameter and pretension are taken from the mooring line for a single floater. The dynamic behavior and safety of the designed mooring system under extreme ocean conditions are analyzed with the commercial software Orcaflex. A numerical study shows the stability and high safety in tension of the designed mooring lines for a floating wave energy farm. The proposed anchorless mooring system for a floating wave energy farm results in a considerable reduction in the length of the mooring line, contributing to the economics of a floating wave energy farm.

• Korean Journal of Pharmacognosy
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• v.50 no.3
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• pp.232-238
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• 2019

Phytochemical study of Ganoderma lucidum (Polyporaceae) let to the isolation of five lanostane triterpenoid (1-5), along with two nitrogen derived phenolic compounds, N-phenylethylformamide (6) and N-acetylphenethylamine (7). The structures of the compounds were determined by 1D and 2D NMR, and MS experiments, as well as by comparison of their data with published values. Compounds 6 and 7 were isolated for the first time from the genus Ganoderma and this species. All the compounds were evaluated for cancer chemopreventive potential based on their ability to inhibit nitric oxide (NO) production induced by lipopolysaccharide (LPS) in mouse macrophage RAW 264.7 cells in vitro. Among the isolates, compounds 2 and 3 showed moderate inhibitory activity against NO production.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.4
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• pp.329-338
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• 2022

This paper provides a case study of development testing and evaluation of design goal of Interferometric SAS (Synthetic Aperture Sonar) system that is developing supported by Civil-Military Technology Cooperation Center in offshore fields. For Deep water operating capabilities evaluation, We have surveyed candidate field, bathymetric mapping and target identification over 200 m depth, East Sea. In testing phase, We have provided environmental information of testing field include water column, seabed and weather condition in real time. And to compare excellency of developing InSAS, we have gather commercial imaging sonar system data with same target. This case study will support the Test Readiness Review of future underwater surveillance system developing via investigate marine testing field environment, testing facilities and planning.

• Journal of Species Research
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• v.12 no.1
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• pp.55-67
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• 2023

Two new records of marine nematodes, belonging to the family Ironidae de Man, 1876, are reported based on the specimens collected from intertidal sediments from the west coast of Korea. Conilia sinensis is characterized by a relatively long body length, a well-developed buccal cavity with three claw-like teeth, the presence of a single spicule with transverse striations, the presence of rib-shaped telamons, and single precloacal supplement. Pheronous donghaiensis is distinguished from other species of the genus by a well-developed buccal cavity with four claw-like solid teeth and minute denticles, relatively short and thick spicules with the central septum, the presence of 8-9 curved tubular-shaped precloacal supplements, and a sharp pointed tail with three small tubular supplements arranged into two rows in males. In this report, we provide a taxonomic description and illustrations of two unrecorded species of the family Ironidae by differential interference contrast microscopy. This is the first taxonomic report on the species of the family Ironidae from Korea.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.507-514
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• 2021

A new free-living marine nematode species of the genus Pseudosteineria Wieser, 1956 affiliated with the family Xyalidae is described based on specimens collected from the sediment of a subtidal benthic environmental habitat in the East Sea, Korea. Pseudosteineria varisetis sp. nov differed from its congeners by the combination of the following characteristics: a relatively long body (1,628-1,691 ㎛ long in males), a circular amphideal fovea situated behind the subcephalic setae, the presence of lateral cuticular alae starting from behind the nerve ring, the presence of eight groups of long subcephalic setae, the presence of irregularly distributed variable lengths of somatic setae on the body, solid spicules (43.2-43.9 ㎛ long) with a cephalated proximal end, a long tubular shaped gubernaculum with dorsal swelling, and a conico-cylindrical tail with two to four terminal setae. In this report, we provide a taxonomic description and illustrations of a new species of the genus Pseudosteineria by differential interference contrast microscopy.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.477-496
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• 2022

During a survey of free-living marine nematodes of Korea, two new marine desmoscolecid nematodes belonging to subgenus Quadricoma Filipjev, 1922 were discovered. Tricoma (Q.) jejuensis sp. nov. and T.(Q.) unipapillata sp. nov. are described based on specimens obtained from washings of coarse sediments from eastern and southern coasts of Korea. Tricoma (Q.) jejuensis sp. nov. is characterized by having 33 quadricomoid body rings and inversion at main ring 23, pentagonal head with truncated anterior end, a pair of ocelli situated at main ring 6, somatic setae comprising of 8 pairs of subdorsal setae and 12 pairs of subventral setae, and relatively short spicules (42-46 ㎛ long). Tricoma (Q.) unipapillata sp. nov. is characterized by 44 quadricomoid body rings and inversion at main ring 32, somatic setae comprising of 7 pairs of subdorsal setae and 10 pairs of subventral setae, globular head truncated anterior end, relatively short and stumpy cephalic setae with cuticular flange, one single naked ventral median genital papillae situated on main ring 20, and spicules with a proximally marked capitulum. Detailed morphological descriptions and illustrations of these two new species are provided in this study.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.579-590
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• 2022

Three free-living marine nematodes(Desmoscolex(Desmoscolex) max Timm, 1970, Daptonema longiapophysis Huang and Zhang, 2010, and Pseudosteineria sinica Huang and Li, 2010) were newly recorded in Korea. Desmoscolex (D.) max was found from subtidal coarse sediment around Wangdolcho in the East Sea. It was characterized by the presence of untypical setae arrangement, obviously elongated triangle-shaped head, long hairy cephalic setae, a long naked tail spinneret, and the absence of peduncle at the base of somatic setae. Daptonema longiapophysis was obtained from intertidal sandy sediments in the southern coast of Korea. It was characterized by the presence of setiform labial sensilla, spicules with a projection on both sides, and gubernaculum with dorso-caudal apophysis. Pseudosteineria sinica was discovered from the intertidal sediment in the Yellow Sea. It was characterized by unobservable amphideal fovea, different lengths of spicules, and gubernaculum with dorso-caudal apophysis. In this study, we provide detailed morphological features of three free-living marine nematodes by differential interference contrast microscopy.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.570-607
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• 2023

The subgenus Tricoma Cobb, 1894 comprises free-living marine nematodes encompassing a total of 83 validated taxa. Within this diversity, twenty-one taxa thrive in the deep sea, while twenty-three are found in coral reefs, flat areas, or green algae. Additionally, eleven taxa inhabit the sublittoral zone at depths exceeding 10 meters, and the remaining taxa are situated on beaches, coasts, or in habitats lacking detailed information. In the course of a survey focused on the East Sea free-living marine nematodes, we identified four new and two previously unrecorded species belonging to the subgenus Tricoma. Specifically, two new species, Tricoma (Tricoma) breviseta sp. nov. and T. (T.) donghaensis sp. nov., were discovered in mud-sandy sediment in deepsea environments below 2000 meters within the Ulleung Basin and Hupo Bank. Two previously unrecorded species [T. (T.) paralucida Decraemer, 1987 and T. (T.) similis Cobb, 1912] and the two newly found species [T. (T.) longicauda sp. nov. and T. (T.) ulleungensis sp. nov.] were obtained from subtidal coarse sand at a depth of 20 meters during a survey of the waters surrounding Ulleungdo Island. The distribution and information on validated taxa within the subgenus Tricoma were systematically collected, reviewed, and cataloged. Detailed morphological features and illustrations of Tricoma species from Korea were provided through the use of differential interference contrast microscopy.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.1
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• pp.25-36
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• 2016

Heavy metals in the stream sediments around Shihwa Lake were studied not only to investigate the characteristics of spacio-temporal distribution but also to assess the pollution degree and ecological risk using various pollution indices. Among metals, Zn had the highest values (1,311 mg/kg) and Hg showed the lowest value (0.261 mg/kg). The order of mean concentrations (mg/kg) of metals was Zn>Cu>Pb>Cr>Ni>Co>As>Cd>Hg in stream sediments around Shihwa Lake. Metal concentrations showed different pollution pattern with industrial region, indicating that these metals originated from different sources and industrial region had higher metal concentration than rural/urban regions. The results of geoaccumulation index (Igeo) showed that the stream sediments were significantly polluted with Cd, Cu, Zn and Pb, indicating moderately to highly polluted by these metals. According to PLI consideration, industrial region was more seriously polluted by metals whereas an rural/urban region was not polluted. About 85% of sampling site for Cr, Ni, Cu, Zn and Pb from industrial regions were exceeded the PEL values. The mPELQ and SQI values derived from PEL of industrial region were classified as 'highly toxic' and 'very poor' and metal pollution level tend to be worse in wet season. This indicates that the industrial activities and stromwater runoff represents an important sources of heavy metals around Shihwa Lake.

• Journal of the Korean Society for Marine Environment & Energy
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• v.20 no.2
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• pp.76-83
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• 2017

In order to investigate the characteristics of water quality and heavy metals in Shihwa Lake, concentration comparisons according to land use types and mass discharge through streams were carried out. Based on classification for streams according to land use types, the concentration of DO, SS, POC, $NO_3$ and Chl-a showed higher concentrations in agricultural areas than in industrial and urban areas. However, COD, DIN, DIP, TN, TP, DOC, TOC and heavy metal concentrations showed relatively high values in industrial areas. The concentrations of water qualities and heavy metals were relatively high in March to May and the concentration decreased in summer seasons (July-August). The averages of stream discharges of water qualities were 1,172 kg/d for SS, 151 kg/d for TN, 11.1 kg/d for TP and 389 kg/d for TOC, respectively. The agricultural area, Jangjunbo(S8), accounted for 47.5%(TP)~75.1%(SS) in the total stream discharges. Cu, Zn and Cd in stream waters were found to be more than 92% of the total discharges in industrial area, showing descending order of Zn>Cu>Ni>Pb>Co>Cd.