• Journal of Environmental Science International
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• v.14 no.8
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• pp.777-783
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• 2005

For the sustainable management of marine ecosystem in Masan Bay, we have to assess the carrying capacity and standard of target water quality. In this research, we assume that all pollutants loads are treated in Dukdong sewage treatment plant, then we simulate the physical-biological model for prediction water quality for the achievement of standard water quality. In 2001 year, for the achievement of COD 2.5 mg/L, we need to reduce COD $90\%$, nitrogen $30\%$, phosphate $90\%$ than that of the present value, According to these results, the water quality of sewage treatment plant is required to treat COD 13.5 mg/L, nitrogen 33.3 mg/L, phosphate 6,0 mg/L. If the sewage treatment plant will be expanded much larger in 2011, it will need to be treated in COD 6.6 mg/L, nitrogen 2.5 mg/L, phosphate 5 mg/L for the achievement of water quality standard in COD 2.5 mg/L.

• Journal of the Korean GEO-environmental Society
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• v.2 no.2
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• pp.41-50
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• 2001

In this study, for the stability analysis of marine embankment, the slope stability analysis and possibility of lateral movement with the marine embankment in ${\bigcirc}{\bigcirc}$harbor were carried out. In order to simulate the practical site condition, the expected maximum sea water level and maximum embankment height were assumed for these analyses. For the evaluation of soil properties, field test, laboratory test, and especially chemical composition analysis were performed for the this analysis. Based on these test results, the soil parameters were determined by applying ground improvement concept under columnar stabilized ground condition and also the effect of staged backfilling was considered under the dredged ground condition. For the optimal design, the stability analyses of embankment with changed height and unchanged height were performed under unimproved soil condition. The result showed that both cases were unstable not only with slope stability but also with lateral movement. Therefore, Deep Mortar Piling was applied for stability analysis and this result was safe. As the conclusion, the deep mortar piling method was suggested as reinforced foundation design for this site.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.5
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• pp.514-521
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• 2007

There has been considerable interest recently in the topic of renewable energy. This is primarily due to concerns about environmental impacts. Moreover, fluctuating and rising oil prices, increases in demand, supply uncertainties and other factors have led to increased calls for alternative energy sources. Small hydropower, especially using water supply system, attracts high attentions because of relatively lower cost and smaller space requirements to construct the plant. Moreover. newly developed positive displacement turbine has high acceptability for the system. Therefore, the purpose of this study is focused on the examination of the performance characteristics and proposition of a optimum design method of the turbine for the improvement of the performance. The results show that newly proposed optimum design method for the turbine has high accuracy of performance prediction and good applicability for the performance improvement of the turbine.

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.4
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• pp.426-435
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• 2005

The lightness of components required in automobile and machinery industries is requiring high strength of components. Therefore this requirement is accomplished as the process of shot-peening method that the compressive residual stress is made on the metal surface as one of various improvement methods. Special research is, therefore, needed about compressive residual stress on the metal surface in the process of shot-peening method. Therefore, in this paper the effect of compressive residual stress of spring steel(JISG SUP-9) by shot-peening on fatigue crack growth characteristics in environmental condition(temperature) and mechanical condition(shot velocity, stress ratio) was investigated with considering fracture mechanics. By using the methods mentioned above, the following conclusions have been drawn. (1) The fatigue crack growth rate(da/dN) of the shot-peened material was lower than that of the un-peened one. In high temperature range. fatigue crack growth rate decreased with increasing temperature range, while fatigue crack growth rate increased by decreasing temperature in low temperature. (2) Fatigue life shows more improvement in the shot-peened material than in the un-peened material. And compressive residual stress of surface on the shot-peen processed operate resistance force of fatigue crack propagation.

• Journal of the Korean Association of Geographic Information Studies
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• v.7 no.3
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• pp.99-107
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• 2004

This study presents an application of GIS technologies to construct the graphic user interface for 3-dimensional exhibition of the results obtained by ocean hydrodynamic model. In coastal management studies, GIS provide a receptacle for scattered data from diverse sources and an improvement of the 3D visualization of such data. Within the frame of a GIS a variety of analytical, statistical and modeling tools can be applied to transform data and make them suitable for a given application. A 3D hydrodynamic model was driven by time-dependent external forcing such as tide, wind velocity, temperature. salinity, river discharge, and solar radiation under the open boundary condition. The Jinhae bay was selected as a case study. Here, we have used GeoMania v2.5 GIS software and its 3D Analyst extension module to visualize hydrodynamic model result that were simulated around the Jinhae bay.

• Journal of the Korean Society for Marine Environment & Energy
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• v.8 no.3
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• pp.148-157
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• 2005

In order to understand distribution characteristics and pollution of heavy metals in the artificial Lake Shihwa in the vicinity of Kyunggi Bay in relation with huge environmental changes, various environmental samples including seawaters, surface sediments and settling particulate matters were collected from Lake Shihwa in 2004. Due to extreme pollutant discharge from various anthropogenic sources such as the Banweol and Shihwa Industrial Complexes and cities, the highest metal concentrations in the samples such as waters, sediments and settling particulate matter were found in inner part of the lake. High metal contents (Cu, Zn and Hg) in sediments were observed at Sts. 2-4 and 9. The contents of Cr, Co, Ni, Cu, Zn and Pb in SPMs were high at St. 5 and low in the outer part of the lake. Spatial distribution of heavy metals were mainly controlled various biogeochemical factors and physical mixing as well as input of industrial and municipal wastewaters. Although tile environmental qualities of heavy metals in the lake have been improved partially due to inflow of outer seawater, it is not clear to reach a good environmental quality. Therefore, further environmental programs should be conducted continuously for environmental improvement.

• Korean Journal of Environmental Biology
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• v.39 no.1
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• pp.6-15
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• 2021

Various biometric and geometric measures were used to discriminate between the morphologically similar river puffer, Takifugu obscurus, tiger puffer, T. rubripes, their hybrids, and their triploid hybrids. The hybrids and triploid hybrids had greater anal fin width, nostril width, and snout length than the parental species (p<0.05). However, they had less caudal peduncle depth, inter-orbital width, head length, and head width(p<0.05). The morphometric and meristic characteristics of the hybrids and triploid hybrids were either intermediate between the parental species or more similar to those of one parental species. However, the external morphology of the hybrids and triploid hybrids was predominantly maternal. The triploid hybrids had asymmetry in the fin rays and gill raker numbers. This study identified phenotypic characteristics by distinguishing the morphological variables of river puffer, tiger puffer, their hybrids, and their triploid hybrids.

• Korean Journal of Remote Sensing
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• v.38 no.4
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• pp.387-394
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• 2022

Coastal upwelling is a significantly imperative process for understanding the interactions between physical and ecological processes and has been investigated incessantly. In this study, we explored the upwelling index, specifically upwelling age (UA). UA enabled us to observe the initiating, sustaining, and decaying upwelling processes. Although the sensitivity of many other geophysical parameters to estimate UA has been investigated, the wind direction has not been evaluated. Thus, we assessed the appropriate wind direction for the UA and obtained efficient upwelling signals from the four coastal stations. Furthermore, we applied the UA and compared it with the satellite sea level anomaly, sea surface temperature, and chlorophyll-a changes to validate how UA depicts their spatial extents. Thus, UA can predict the timing of coastal upwelling events using predicted geophysical parameters.

• The Journal of Fisheries Business Administration
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• v.45 no.2
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• pp.1-13
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• 2014

This study analyzes patent trends regarding farming-related technologies such as breeding or nursery technology, production systems, and new cultivation methods in order to provide objective patent information about the trends of R&D on marine products' proliferation or farming. Presently, in Korea, we try to secure marine living resources through the formation of artificial resources instead of environmental improvement policy or resource management policy. However, this is not about eliminating the causes of marine environment destruction but just the policy for improvement, so it is needed to revise the related policy with more ultimate measures. And it is necessary to develop technology that can secure the rights by integrating patent application strategies from the stage of R&D for medicine that can be utilized in chief farming countries and provide intensive support for the research centering around strategic varieties for farming in each region as well as strategic national farming varieties afterwards. Also, the analysis shows that it is urgent to make applications overseas based on domestic applications in order to develop technology that can be commercialized in not just Korean but overseas market as well.

• Geomechanics and Engineering
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• v.17 no.5
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• pp.453-464
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• 2019

Soft marine soil has high fine-grained soil content and in-situ water content. Thus, it has low shear strength and bearing capacity and is susceptible to a large settlement, which leads to difficulties with coastal infrastructure construction. Therefore, strength improvement and settlement control are essential considerations for construction on soft marine soil deposits. Biopolymers show their potential for improving soil stability, which can reduce the environmental drawbacks of conventional soil treatment. This study used two biopolymers, an anionic xanthan gum biopolymer and a cationic ${\varepsilon}-polylysine$ biopolymer, as representatives to enhance the geotechnical engineering properties of soft marine soil. Effects of the biopolymers on marine soil were analyzed through a series of experiments considering the Atterberg limits, shear strength at a constant water content, compressive strength in a dry condition, laboratory consolidation, and sedimentation. Xanthan gum treatment affects the Atterberg limits, shear strength, and compressive strength by interparticle bonding and the formation of a viscous hydrogel. However, xanthan gum delays the consolidation procedure and increases the compressibility of soils. While ${\varepsilon}-polylysine$ treatment does not affect compressive strength, it shows potential for coagulating soil particles in a suspension state. ${\varepsilon}-Polylysine$ forms bridges between soil particles, showing an increase in settling velocity and final sediment density. The results of this study show various potential applications of biopolymers. Xanthan gum biopolymer was identified as a soil strengthening material, while ${\varepsilon}-polylysine$ biopolymer can be applied as a soil-coagulating material.