• Journal of Korea Water Resources Association
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• v.53 no.7
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• pp.521-531
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• 2020

The purpose of this study is to suggest a quantitative assessment of wetland damage considering the effects of topsoil erosion and deposition from rainfall. In the Cheoncheon Basin located upstream of the Yongdam Dam, 16 wetlands are located, but the lacustrine and small palustrine wetland were analyzed for possible damage to erosion and deposition. As a result of applying typhoon events in 2002 and 2003, the sediment load from the upper basin was the highest at 2.30% (22,548 ㎥) of low water capacity. The average sediment load in the mountain areas was found to be 0.03% of the low water capacity, and it was analyzed to be less damaging than the lacustrine with relatively large watershed. as a result of the model, the lacustrine wetland, where a large area is used as agricultural land, shows a high probability of sediment yield, so it is highly likely to damage the wetland by topsoil erosion.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.11a
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• pp.57-61
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• 2004

According to the research result of existing regarding the seabed organic sediment, contamination it flows from the land and the sea become the enemy in the coastal water. It was caused with the summer season water temperature rise and dispersing recall respect advancement. Phosphorus which is a main reason of red tide actual condition came to reveal vast quantity with the facts that it gushes. Specially, in the case of the coastal closing waters and the nursery, as the corpse and the fresh fish washing veterinarian was imbrued, it is the actual condition where is more deepened. Consequently the development of shallow layer dredging method of that suction power which is stabilized is demanded to be able to dredge only the sediment layer which has not become the pressure and is a main reason of being imbrued. The dredging methods using the pressure difference minimize the suction of the seabed sediment. This method is stable that suction power which occurs from guard difference of the guard and the guard of the dredging system inland water. That's why it is possible to sort dredging of the organic sediment ranging in upper layer sediment and it will be able to expect the minimization of dredging quantity. Increase of the expense that it followsin orthocenter with the fact will not grow. Because the pressure difference of the dredger inland water is occurred by the suction power. Maintenance administrative costs are reduced, because the one of smallest dredging system maneuvers and the barge which affixes an integrated operation system is mainly in a resting. To reduce a dredging hour, it will be able to solve in the condensed water as operating the jar guard post.

• Journal of the Korean Institute of Landscape Architecture
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• v.18 no.4
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• pp.45-71
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• 1991

The landscape systems in Korean island settlements can be recognized as results of ingabitants' ecological adptation to the isolated environment with the limited natural resources. Both the fishery dominant industry in island society and ecological nature of its environments seem to have influenced on inhabitants' environmental cognition as well as the physical landscape of island villages such as its location, spatial pattern in each village, housing form and so on. This study was done mainly by both refering to the related documents and direct observations in case study areas, and results of the study can be summarized as follows. 1. In general, the landscape of an individual island seems to take more innate characteristics of island's own, corresponding to the degree of isolation from mainland. That is, while the landscape of island in neighboring waters takes both inland-like and island-innate landscape character at the same time, the one in the open sea far from land takes more innate landscape character of all island's own in the aspects of village location, land use and housing density etc. 2. The convex landform of most islands brings about more centrifugal village allocation than centripetal allocation in most inland villages. And thus most villages in each island face extremely diverse directions different from the south facing preference in most inland rural villages. 3. Most island villages tend to be located along the ecologically transitional strip between land and sea, so called 'line of life', rather than between hilly slope and flat land as being in most inland village locations. So they are located with marine ecology bounded fishing ground ahead and land ecology bounded agricultural site at the back of them. 4. The settlement pattern of the island fishing villages shows more compact spatial structure than that of inland agricultural villages, due to the absolute limits of usable land resources and the adaptation to the marine environment with severe sea winds and waves or for the easy accessability to the fishing grounds. And also the managerial patterns of public owned sea weed catching ground, which take each family as the unit of usership rather than an individual, seem to make the villagescape more compact and the size of Individual residence smaller than that of inland agricultural village. 5. The folk shrine('Dand') systems, in persrective of villagescape, represent innate environmental cognition of island inhabitants above all other cultural landscape elements in the island. Usually the kinds and the meanings of island's communal shrine and its allocative patternsin island villagescape are composed of set with binary opposition, for example 'Upper shrine(representing 'earth', 'mountain' or 'fire')' and 'Lower Shrine(representing 'sea', 'dragon' or 'water') are those. They are usually located at contrary positions in villagescape each other. That is, they are located at 'the virtical center or visual terminus(Upper shrine at hillside behind the village)' and 'the border or entrance(Lower Shrine at seashore in front of the village)'. Each of these shirines' divinity coincides with each subsystem of island's natural eco-system(earth sphere vs marine sphere) and they also contribute to ecological conservation, bonded with the 'Sacred Forest(usually with another function of windbreak)' or 'Sacred Natural Fountain' nearby them, which are representatives of island's natural resources.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.1
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• pp.41-48
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• 2015

Juvenile banded catfish(Pseudobagurus fulvidraco, mean length $10.4{\pm}0.37cm$ and mean weight $14.5{\pm}0.46g$) were exposed to several nitrite(${NO_2}^-$) concentrations for 96h at pH levels of $6.18{\pm}0.54$, $6.5{\pm}0.30$ and $7.07{\pm}0.22$. The result showed that cumulative mortalities of fish to ${NO_2}^-$ levels of 12.4, 19.8, 33.9 and 53.6 mg/L at pH levels of $6.18{\pm}0.54$ were 20, 25, 40 and 85%, respectively. At pH $6.5{\pm}0.54$, mortalities to ${NO_2}^-$ 22.4, 36.4, 45.3 and 63.2 mg/L were 25, 35, 50 and 100%, respectively. At pH $7.07{\pm}0.22$, mortalities to ${NO_2}^-$ 25.5, 45.7, 56.3 and 66.4 mg/L were 0, 55, 70 and 100%, respectively. The 96h-$LC_{50}$(median lethal concentration, $LC_{50}$) of fish to several ${NO_2}^-$ concentrations at pH levels of $6.18{\pm}0.54$, $6.5{\pm}0.30$ and $7.07{\pm}0.22$ were assessed in these experiments. 96h-$LC_{50}$ at pH levels of $6.18{\pm}0.54$, $6.5{\pm}0.30$ and $7.07{\pm}0.22$ were 32.68, 40.49 and 45.85 mg/L, respectively. It indicated that acute toxicity of ${NO_2}^-$ to juvenile banded catfish increased with low levels of pH and lengthening of exposure time to ${NO_2}^-$. In particular, smaller fish(mean weight $14.5{\pm}0.46g$) were more sensitive to ${NO_2}^-$ than larger fish(mean weight $81.7{\pm}1.42g$; not published). The 96h-$LC_{50}$ of juvenile banded catfish to ${NO_2}^-$ would be primary guideline for water quality management in the intensive culture system such as RAS and BFT.

• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.115-122
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• 2020

Due to the climate change, torrential rain downpours unprecedentedly, and urban areas repeatedly suffer from the inundation damages, which cause miserable loss of property and life by flooding. Two major reasons of urban flooding are river inundation and inland submergence. However, most of previous studies ignored the comprehensive mechanism of those two factors, and showed discrepancy and inadequacy due to the linear summation of each analysis result. In this study, river inundation and inland flooding were analyzed at the same time. Petrov-stabilizing scheme was adopted to capture the shock wave accurately by which river inundation can be modularized. In addition, flux-blocking alrotithm was introduced to handle the wet and dry phenomena. Sink/source terms with EGR (Exponentially Growth Rate) concept were incorporated to the shallow water equations to consider inland flooding. Comprehensive simulation implementing inland flooding and river inundation at the same time produced satisfactory results because it can reflect the counterbalancing and superposition effects, which provided accurate prediction in flooding analysis.

• Korean Journal of Ichthyology
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• v.32 no.4
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• pp.232-238
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• 2020

The objective of the present study was to investigate fish farm and growth performances of Chinese muddy loach (Misgurnus mizolepis) under indoor and outdoor aquaculture conditions for the domestic loach aquaculture industry. The investigation was conducted from August 2017 to October 2019 at one indoor farm (D-site) and two outdoor farms (P1-site and P2-site). Results showed that WG (weight gain), DWG (daily weight gain), and SWG (specific weight gain) based on growth measurements were 175.27±36.2%, 7.98±3.3%, and 0.94±0.2% at D-site, 320±34%, 4.07±0.6%, and 0.55±0.1% at P1-site, and 295.9±53%, 4.15±0.5%, and 0.62±0.1% at P2-site, respectively. WG was higher in outdoor farms (P1-site and P2-site), while DWG and SWG were higher in the indoor farm (D-site). Such differences of the present study might be due to differences in growth, water quality, plant and sale frequency depending on aquaculture types. In particular, outdoor farms takes more than a year to have sales whereas indoor farms can have sales three times in a year.

• Journal of the Korean Professional Engineers Association
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• v.39 no.6 s.189
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• pp.51-56
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• 2006

The important role of canal is moving goods and the canals from all over the world has contributed much to method of transporting goods. But, the canal system accounts rfor 25% of the total moving goods. One of its main goals is to reduce overland transportation costs were 30% more expensive than moving goods over water. We plan to build a Korea inland canal system and need to from a scheme of building a multi canal. We should consider positive aspect of this plan, on the other hand a study of the conal's environmental impact is required prior to beginning any construction. Finally, offer our opinion on the vision of Korea inland canal that aspect5 of national land development.

• Journal of Fisheries and Marine Sciences Education
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• v.23 no.2
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• pp.210-220
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• 2011

The Keyongin Inland waterway will connect with Han-River and the Northen part of the Incheon-seaway and this way will be opened at the early of October this year. In this regard, the Incheon container terminal is under constructing for 1,000 TEU & 550 TEU container vessels at the place of leftside of the Seohae lockgate. However the terminal length is not still fixed due to at a great expenses of construction and dosposal matter of the dredged soil. So this paper will suggest the optimum berth length by using the full mission shiphandling simulator for berthing and unberthing shipmaneuvering. And also evaluates the design standard of harbor construction rules and analysis optimum berth length against ship's length for safe shiphandling at terminals in accordance with the customary practices of the major ports in Korea.

• Animal Systematics, Evolution and Diversity
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• v.21 no.1
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• pp.31-43
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• 2005

Three harpacticoid species of the genus Onychocamptus are reported from the inland waters of South Korea: O. vitiospinulosa (Shen and Tai), O. mohammed (Blanchard and Richard) and O. bengalensis (Sewell). Of these, O. vitiospinulosa and O. mohammed are newly added to Korean copepod fauna. Onychocamptus vitiospinulosa is redescribed. Systematic accounts on the morphological details and the intraspecific variabilities are provided with a key to the Onychocamptus species from Korea.

• Korean Journal of Environmental Biology
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• v.40 no.4
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• pp.651-659
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• 2022

This study was conducted to investigate the effects of different water temperatures (8, 11, 14 and 17℃) on growth, survival and hematological parameters of juvenile chum salmon(Oncorhynchus keta) for eight weeks. At the end of the experiment, at 14℃, the final body weights of the O. keta group were the highest compared to the other groups. Also, the O. keta showed a higher tendency in the 14℃ group than the 8, 11, and 17℃ groups in terms of growth performances, including specific growth rate (SGR), feed conversion ratio (FCR), feed efficiency (FE), weight gain (WG), and condition factor (CF). The survival rate (SR) was 100% at 8 and 11℃ groups, 96% at 14℃ group and 98% at 17℃ group. In the plasma components, the alanine aminotransferase (ALT) was significantly decreased at 17℃ group, whereas there was no significant change in the albumin (ALB), total protein (TP), sodium (Na⁺), potassium (K⁺) and chloride (Cl^-) levels. Among the whole-body composition of salmon, moisture, crude protein, and ash were not significantly affected by water temperature. However, crude lipid in the 8℃ group was significantly higher than in other water temperature groups. The results of this study demonstrated that the optimal temperature to stable growth performance for juvenile O. keta was 14℃.