• Journal of Korean Society of Environmental Engineers
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• v.37 no.6
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• pp.349-356
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• 2015

Trace metals concentrations in the tissue of edible marine fish (4 species), olive flounder (Paralichthys olivaceus), Korean rockfish (Sebastes schlegelii), file fish (Stephanolepis cirrhifer) and abbysal searobin (Lepidotrigla abyssalis), collected near the Yongho wharf in Busan were determined to assess the potential human health risk (HRA) of trace metals by fish consumption. Levels of Li, Cr, Ni, Cu, Zn, As, Cd, and Pb in the fish tissue were $0.005{\pm}0.009$, $0.77{\pm}0.30$, $0.29{\pm}0.34$, $0.49{\pm}0.14$, $15.96{\pm}2.52$, $10.62{\pm}4.67$, $0.001{\pm}0.002$, and $0.045{\pm}0.06mg/kgdw$ respectively. The estimated daily intakes of Cu and Zn and the estimated weekly intakes of As, Cd, and Pb from the fish collected near the Yongho wharf were 0.0032, 0.054-0.18% of PMTDI (provisional maximum tolerable daily intake) and 13, 0.0041, 0.020% of PTWI (provisional tolerable weekly intake) which were set to evaluate the food safeties by the JFCFA (The Joint FAO/WHO Expert Committee on Food Additives). Lifetime cancer risk and target hazard for local residents due to those fish consumption were found to be negligible.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.3
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• pp.292-303
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• 2018

Objectives: This study aims to analyze manganese (Mn) concentrations in maternal and cord bloods at delivery and to estimate the Mn exposure risk for fetuses whose mothers were occupationally exposed to Mn. Materials and Methods: Forty-six pairs of maternal and cord blood samples were collected at delivery from mothers who were occupationally unexposed to Mn. Mn concentrations of blood were analyzed by graphite furnace atomic absorption spectrometer. Mn exposure levels for fetuses of female workers were estimated by simulating two working exposure scenarios. Results: The geometric mean concentration of Mn in maternal and cord blood were $27.0(1.34){\mu}g/L$, $46.6(1.25){\mu}g/L$, respectively. Transfer ratios of Mn from maternal to cord blood were $1.81{\pm}0.62$, which indicated that the Mn concentrations in cord blood were higher than those in maternal blood. Mn concentrations in cord blood for the worse or general scenarios were estimated to $22.3-1,881{\mu}g/L$ and $1.59-308{\mu}g/L$, respectively. The probabilities of exceeding $74{\mu}g/L$, which was adopted as a reference level reported in a previous study, were 95% and 44% for the two scenarios, respectively. Conclusions: Comparable levels of Mn exposure in maternal or cord blood to those in this study have shown various health effects in previous studies. This suggests that Mn exposure levels in mothers and fetuese in Korea need to be monitored and managed. In addition, female workers who are occupationally exposed to Mn should be protected from the exposure since their fetuses can be exposed to Mn at risky levels during their pregnancy.

• Ocean and Polar Research
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• v.33 no.3
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• pp.235-253
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• 2011

The annual variation of mesozooplankton community in the Jangmok harbor of Jinhae Bay was studied in relation to environmental variables. Sampling was carried out weekly from January to December 2009. During the study periods, mesozooplankton community consisted of 44 taxa and the annual mean abundance was 8308 inds. $m^{-3}$. The maximum abundance was observed to be 50043 inds. $m^{-3}$ in August and the minimum in April with 1013 inds. $m^{-3}$. Of these, Penilia avirostris, cirripedia larvae, Evadne tergestina, Acartia omorii, Oikopleura s, Paracalanus parvus s. l., Eurytemora pacifica, Podon s, Oithona s, and Acartia steueri were observed as dominant species in Jangmok bay and they also contributed to 79% of total mesozooplankton. According to non-metric multidimensional scaling (nMDS) and cluster analysis based on the mesozooplankton community data from each season, the community was divided into three groups. The first group included appearence species in winter and spring season, which is mainly dominated the copepod such as A. omorii and E. pacifica. The second and third group was composed with observed species in summer and autumn, respectively. Based on the SIMPER (similarity percentages), P. avirostris in summer and cirripedia larvae in autumn were significantly dominated. Our results indicate that although the mesozooplankton abundances in Jangmok harbor fluctuated abruptly, its annual variation was strongly influenced by water temperature.

• Korean Journal of Ecology and Environment
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• v.54 no.4
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• pp.265-271
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• 2021

Intertidal mud crab (Macrophthalmus japonicus) is an organism with a hard chitinous exoskeleton and has function for an osmotic control in response to the salinity gradient of seawater. Crustacean exoskeletons change in their natural state in response to environmental factors, such as changes in the pH and water temperature, and the presence of pollutant substances and pathogen infection. In this study, the ecotoxicological effects of irgarol exposure and heavy metal distribution were presented by analyzing the surface roughness of the crab exoskeleton. The exoskeleton surface roughness and variation reduced in M. japonicus exposed to irgarol. In addition, it was confirmed that the surface roughness and variation were changed in the field M. japonicus crab according to the distribution of toxic heavy metals(Cd, Pb, Hg) in marine sediments. This change in the surface roughness of the exoskeleton represents a new end-point of the biological response of the crab according to external environmental stressors. This suggests that it may affect the functional aspects of exoskeleton protection, support, and transport. This approach can be utilized as a useful method for monitoring the aquatic environment as an integrated technology of mechanical engineering and biology.

• Journal of the Korean Society for Marine Environment & Energy
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• v.19 no.1
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• pp.18-24
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• 2016

Mineral carbonation is a technology for permanently storing carbon dioxide by reacting with metal oxides containing calcium and magnesium. In this study, we used sea water and alkaline industrial by-product such as paper sludge ash (PSA) for the storage of carbon dioxide through direct carbonation. We found the optimum conditions of both sea water content (mixing ratio of sea water and PSA) and reaction time required in the direct carbonation through various experiments using sea water and PSA. In addition, we compared the amounts of carbon dioxide storage with the cases when sea water and ultra-pure water were separately used as solvents in the direct carbonation with PSA. The amount of carbon dioxide storage was calculated by using both solid weight increase through the carbonation reaction and the contents of carbonate salts from thermal gravimetric analysis. PSA particle used in this study contained 67.2% of calcium. The optimum sea water content and reaction time in the carbonation reaction using sea water and PSA were 5 mL/g and 2 hours, respectively, under the conditions of 0.05 L/min flow rate of carbon dioxide injected at $25^{\circ}C$ and 1 atm. The amounts of carbon dioxide stored when sea water and ultra-pure water were separately used as solvents in the direct carbonation with PSA were 113 and $101kg\;CO_2/(ton\;PSA)$, respectively. The solid obtained through the carbonation reaction using sea water and PSA was composed of mainly calcium carbonate in the form of calcite and a small amount of magnesium carbonate. The solid obtained by using ultra-pure water, also, was found to be carbonate salt in the form of calcite.

• Journal of Convergence for Information Technology
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• v.10 no.6
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• pp.1-7
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• 2020

The demand on the underwater communications is extremely increasing in searching for underwater resources, marine expedition, or environmental researches, yet there are many problems with the wireless communications because of the characteristics of the underwater environments. Especially, with the underwater wireless networks, there happen inevitable delay time and spacial inequality due to the distances between the nodes. To solve these problems, this paper suggests a new solution based on ALOHA-Q. The suggested method use random NAV value. and Environments take reward through communications success or fail. After then, The environments setting NAV value from reward. This model minimizes usage of energy and computing resources under the underwater wireless networks, and learns and setting NAV values through intense learning. The results of the simulations show that NAV values can be environmentally adopted and select best value to the circumstances, so the problems which are unnecessary delay times and spacial inequality can be solved. Result of simulations, NAV time decreasing 17.5% compared with original NAV.

• Ocean and Polar Research
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• v.39 no.2
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• pp.85-106
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• 2017

The Lago Sofia conglomerate in southern Chile is a deep-marine gravelly deposit, which is hundreds of meters thick and kilometers wide and extends laterally for more than 100 km, filling the foredeep trough of the Cretaceous Magallanes Basin. For understanding the depositional processes and environments of this gigantic deep-sea conglomerate, detailed analyses on sedimentary facies, architecture and paleoflow patterns were carried out, highlighting the differences between the northern (Lago Pehoe and Lago Goic areas) and southern (Lago Sofia area) parts of the study area. The conglomerate bodies in the northern part occur as relatively thin (< 100 m thick), multiple units intervened by thick mudstone-dominated sequences. They show paleoflows toward ENE and S to SW, displaying a converging drainage pattern. In the southern part, the conglomerate bodies are vertically interconnected and form a thick (> 400 m thick) conglomerate sequence with rare intervening fine-grained deposits. Paleoflows are toward SW. The north-to-south variations are also distinct in sedimentary facies. The conglomerate bodies in the southern part are mainly composed of clast-supported conglomerate with sandy matrix, which is interpreted to be deposited from highly concentrated bedload layers under turbidity currents. Those in the northern part are dominated by matrix- to clast-supported conglomerate with muddy matrix, which is interpreted as the products of composite mass flows comprising a turbidity current, a gravelly hyperconcentrated flow and a mud-rich debris flow. All these characteristics suggest that the Lago Sofia conglomerate was formed in centripetally converging submarine channels, not in centrifugally diverging channels of submarine fans. The tributaries in the north were dominated by mass flows, probably affected by channel-bank failures or basin-marginal slope instability processes. In contrast, the trunk channel in the south was mostly filled by tractive processes, which resulted in the vertical and lateral accretion of gravel bars, deposition of gravel dunes and filling of scours and channels, similar to deposits of terrestrial gravel-bed rivers. The trunk channel developed along the axis of foredeep trough and its confinement within the trough is probably responsible for the thick, interconnected channel fills. The large-scale architecture of the trunk-channel fills shows an eastward offset stacking pattern, suggesting that the channel migrated eastwards most likely due to the uplift of the Andean Cordillera.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.44 no.4
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• pp.282-293
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• 2008

In order to develop the substitutive materials for natural baits of swimming crab pots, the attracting effects of swimming crab such as the preference of baits which were made of the by-products of marine and stock raising through the water tank experiments and fishing experiments. On the investigation of mean entrapped catch number to the pot by the baits after putting the 4 kinds of baits, mackerel(M), mackerel with grinded mackerel s internals($MM_I$), mackerel with tuna s internals$MM_I$) and makerel with grinded krill(MK) each in one pot by turns, $MM_I$ and MK were entrapped mean 3.9(13.0%) and they were a little more comparing to M, and $MT_I$ is least with mean 2.1(7.0%)(F=12.913, P < 0.05). Otherwise, on the preference investigation of swimming crabs by the baits after putting the 4 kinds of baits in the 4 pots each, M was entrapped mean 3.0(10%), but $MM_I$, $MT_I$ and MK were mean 1.2(4.0%), 1.0(3.3%) and 1.5(5.0%) each and they were only 30-50% of M(F=13.398, P < 0.05). On the preference investigation of swimming crabs by the 5 kinds of baits, mackerel(M), and krill(K), manila clam($M_C$), pig s fat($P_F$) and chicken s head($C_H$) which were used in substitutive baits, M was entrapped mean 3.2(10.7%), but K was about 50% of catch of M with mean 1.6(5.3%), and $M_C$, $P_F$ and $C_H$ were very few with mean 0.1-0.2(0.3-0.7%)(F=89.186, P < 0.05). On the preference investigation of swimming crabs by the pots which were put each the 3 kinds of baits, original krill(K), grinded krill with gluten and soybean oil cake($K_GGS$) and grinded krill with gluten, soybean oil cake and glycine($K_GGSG_L$) in the blue fluorescent hexahedral plastic bait cages(BF), and which were put the mackerel(M) in the non-fluorescent hexahedral red plastic bait cage($RF_N$), it was entrapped mean 3.0(10.0%) in the pot which was put the mackerel in the $RF_N$, and the same level in the pots which were put the K and $K_GGSG_L$ in the BF, but it was mean 2.0(6.7%) in the pots which was put the $K_GGS$ in BF and it was decreased by 30% of catch comparing to $RF_N$(F=3.750, P < 0.05). On the preference investigation of swimming crab by the pots which was put grinded tuna with gluten, soybean oil cake and glycine($T_IGSG_L$) in the blue fluorescent hexahedral plastic bait cage(BF), and which was put mackerel(M) in the nonfluorescent hexahedral red plastic bait cage($RF_N$), it was entrapped mean 3.3(11.0%) in the pot which was put mackerel in $RF_N$, and mean 2.7(9.0%) in the pot which was put $T_IGSG_L$ in BF and it was about 15% less comparing to use bait M(t=1.387, P < 0.05). As a results of fishing experiments, a plan for enhancing catching efficiency of $T_IGSG_L$ will be required because catching efficiency of $T_IGSG_L$, alternative bait, was half of fish catching efficiency of natural bait using mackerel. Fishing experiments were conducted 3 times using reinforced substitutive artificial bait that is reinforced attractive effect of $T_IGSG_L$ and composed of tuna intestine, grinded mackerel, gluten, soybean cake, glycine and alanine($T_IM_GGSG_LA$). Catching efficiency of $T_IM_GGSG_LA$ was about 80% of that of natural bait made of mackerel.

• Journal of Life Science
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• v.23 no.3
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• pp.415-425
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• 2013

This study compared the characteristics of five Bacillus strains capable of aerobic and anaerobic growth, CBW3, CBW4, CBW9, CBW14 and EBW10. They were isolated and selected from a polychaete, Perinereis aibuhitensis, which is known as a good degrader of organic compounds in marine wetland. Based on a 16S rRNA sequence, CBW3 and CBW14 were found to share more than 99.8% similarity with B. nanhaiensis, B. arsenicus and B. barbaricus. CBW4, CBW9 and EBW10 shared 92.7%, 99.8%, and 99.8% similarity with B. anthracis, B. algicoa and B. thuringiensis, respectively. The temperature, salinity, and pH ranges of the cell growth of the Bacillus strains were $4-45^{\circ}C$, 0-17%, and pH 5-pH 9, respectively. All Bacillus strains were found to exhibit enzyme activities for the degradation of casein and starch. Notably, strain EBW10 exhibited the enzyme activities for all the tested macromolecules, DNA, casein, starch, cellulose, and four kinds of Tweens, which suggests the possibility that it had protease, amylase, cellulose, and lipase. All five Bacillus strains had alkaline phosphatase activities, and the strains CBW3, CBW4, and EBW10 also had acid phospatase. Strains CBW3 and EBW10 exhibited the enzyme activities both for esterase (C4) and esterase lipase (C8). The analysis of fatty acids revealed that in all strains, major fatty acids were anteiso $C_{15:0}$ and iso $C_{15:0}$.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.4
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• pp.239-247
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• 2013

Recently renewable energy such as offshore wind energy takes a higher interest due to the depletion of fossil fuel and the environmental pollution. This paper deals with multi-body dynamics (MBD) analysis technique for offshore wind turbine system considering aerodynamic loads and Thevenin equation used for determination of electric generator torque. Dynamic responses of 5MW offshore wind turbine system are evaluated via the MBD analysis, and the system is the horizontal axis wind turbine (HAWT) which generates electricity from the three blades horizontally installed at upwind direction. The aerodynamic loads acting on the blades are computed by AeroDyn code, which is capable of accommodating a generalized dynamic wake using blade element momentum (BEM) theory. In order that the characteristics of dynamic loads and torques on the main joint parts of offshore wind turbine system are simulated similarly such an actual system, flexible body modeling including the actual structural properties are applied for both blade and tower in the multi-body dynamics model.