• Magazine of RCR
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• v.9 no.4
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• pp.33-41
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• 2014

• Proceedings of the KSRS Conference
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• v.1
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• pp.247-249
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• 2006

The objective of this study is to detect a inter-tidal topographic change in a decade. Waterline extraction is a one of widely used method to generate digital elevation model (DEM) of tidal flat using multi-temporal optical data. This method has been well known that it is possible to construct detailed topographic relief of tidal flat using waterlines In this study, we generated two sets of tidal flat DEM for the southern Ganghwado. The DEMs showed that the Yeongjongdo northern tidal flat is relatively high elevation with steep gradients. The Ganghwado southern tidal flat is relatively low elevation and gentle gradients. To detect the morphologic change of tidal flat during a decade, we compared between early 1990's DEM and early 2000's DEM. Erosion during a decade is dominant at the west of southern Ganghwado tidal flat, while sedimentation is dominant at the wide channel between the southern Ganghwado and Yeongjongdo tidal flats. This area has been commonly affected by high current and sedimentation energy. Although we are not able to verify the accuracy of the changes in topography and absolute volume of sediments, this result shows that DEM using waterline extraction method is an effective tool for long term topographic change estimation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5826-5834
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• 2014

This paper examined the changes in flow patterns due to a blockage of tidal currents in the sea areas between Incheon North Port and Yeomha Channel when it would be influenced by the construction of the Incheon North Port Yeongjongdo dredged soil dumping ground and Incheon Bay tidal power plant. The numerical simulation was performed for three cases: before and after constructing the Incheon North Port Yeongjongdo dredged soil dumping ground and after the construction of the sea-dyke on the east side of the Incheon Bay tidal power plant. The simulation results showed that the tidal directions and currents velocity were similar before and after the construction of the Yeongjongdo dredged soil dumping ground. After the construction of the East Sea-dyke of Incheon tide power plant, however, the tidal currents patterns changed significantly due to flow blockage toward Gyeonggi Bay. The main flow was formed in the north-south direction, and the tidal currents velocity increased slightly on the downstream areas (A,B,C) of Hodo, which is the entrance of the Ara Waterway. The tidal currents at the mouth(D) of Yeomha Channel decreased significantly. The tidal currents of the west side of Se-eodo and the east side of the sea-dyke were rotary currents. The results of this study will provide basic data for the environmental impact assessment and the operation of the Gyeongin Ara Waterway.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.725-732
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• 2003

It was achieved that Rowecell test for this undisturbed sample was picked by Block sampler($\phi$:250mm, L:500mm) and hydraulic piston sampler($\phi$:76mm, L:850mm) in the marine clay of YONGYUDO and YEONGJONGDO in this research. Ratio of coefficient of consolidation was analyzed through comparison with C$\_$h/ by CPTu and C$\_$v/ and C$\_$h/ by existent consolidation test. According to analysis, coefficient of consolidation of block sample is fairly greater than coefficient of consolidation of piston sample. And the bigger diameter of undisturbed sample, sample disturbance could know decreasing. Coefficient of consolidation by Rowecell test measured more greatly than coefficient of consolidation by existent consolidation test. Rowecell test could know decreasing consolidation rate because of smear effect by Mandrel injection. Also, C$\_$h/ by CPTu shows deviation by each analysis method, selection of suitable analysis method judged by important leading in the coefficient of consolidation.

• The Journal of Fisheries Business Administration
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• v.25 no.1
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• pp.19-35
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• 1994

The objective of this study is to analize the system of legal compensation for the fishery loses caused by public works and to suggest alternatives on the current compensation system. Korea government has been performing reclamation activities in coastal region to conduct farm, urban and industrial area, and such activities are still going on in Yeongjongdo airport area, Saemangeum area and so on. Reclamation interrupts fishing activities in or around the reclaiming area, therefore, the compensation for fishery losses incurred by fishermen should be made. The system of legal compensation in Korea, however, is based on the land compensation, and the regulation of the compensation for fishery losses in the Fishery Act can not be applied for the compensation of public works because the procedure of the compensation in the Fishery Act is different from its cause of action. Therefore, this study is caried out to suggest a resonable compensation procedure and to provide a basis for establishing legal system.

• International Journal of Railway
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• v.8 no.1
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• pp.21-29
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• 2015

This study focuses on the performance enhancement of the levitation and guidance control system in urban and medium-to high-speed magnetic levitation trains. A levitation control system, which is currently being tested in Yeongjongdo, is a single controller that is neither designed nor produced on the basis of redundancy. Hence, vehicular stability and reliability should be improved for the situation in which levitation failure occurs because of a breakdown in a controller during vehicle operation. In addition, the control system should be developed to control electromagnetic levitation considering changes in normal force according to changes in the driving force of the propulsion system.

• The Korean Journal of Ecology
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• v.26 no.5
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• pp.223-236
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• 2003

The vegetation in this study area was divided into 10 plant communities: Pinus thunbergii, P. densiflora, Quercus acutissima, Q. mongolica, Q. serratea, Q. variabilis, Q. aliena, Q. dentata, Carpinus coreana, Betula davurica and 3 afforestations; Pinus rigida, Robinia pseudo-acacia, Castanea crenata. The dominant species in each stratum as determined by R-NCD appeared to be Q. acutissima, P. densiflora, Platycarya strobilacea, Sorbus alnifolia and Q. aliena in the tree-2 layer, Rhododendron mucronulatum, P. strobilacea, Q. serrata, Q. aliena and Q. acutissima in the shrub layer, and Carex lanceolata, C. humilis, R. mucronulatum, Mischanthus sinensis var. purpurascens and Oplismenus undulatifolius in the herb layer. The distribution of diameter at breast height(DBH) showed the highest percentage (56%) in the range of 2∼10㎝ in the study area and it was investigated as being in the restoration phase after disturbance. The average of the age of trees was under 40-years-od. The pH of soil collected at each site appeared to be within the range between 4.53 and 5.10(the average of 4.73) in each community, organic matters appeared higher than the value in Q. mongolica, P. rigida, C. crenata communities compared to P. thunbergii, P. densiflora communities. And soil organic matters and total nitrogen were highly correlated with their contents.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.29-32
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• 2007

Tidal channel development is influenced by sediment type, grain size, composition and tidal current. Tidal channels are usually characterized by channel development, density and shape. Quantitative analysis of tidal channels using remotely sensed data have rarely been studied. The objective of this study is to quantify tidal channels in terms of fractal dimension and compare different inter-tidal channel patterns. For the fractal analysis, we used Box counting method which had been successfully applied to streams, coastlines and others linear features. For a study, the southern part of Ganghwado tidal flats was selected where is famous for high dynamics of tidal currents and vast tidal flats. This area has different widths and lengths of tidal channels. IKONOS and Komsat-2 MSC images were used for extracting tidal channels, and the Box counting method was applied to obtain fractal dimensions (D) for each tidal channel. Yeochari area possesses channels with linear pattern and less dense development and accordingly show low D values ranging from 1.037 to 1.038. On other hands, area (near Donggumdo and Yeongjongdo ) of dendrites channel pattern and dense development resulted in high D values from 1.2057 to 1.2667. Also, area possesses channels with linear pattern had low density about $18{\sim}24%$. Area of dendritic channel pattern had high density about $34{\sim}69%$. The difference of fractal dimensions about 0.2 according to channel development in tidal flats is relatively large enough to use as an index for tidal channel classification. Also, area where channels showed linear pattern had low density about $18{\sim}24%$. Area of dendritic channel pattern had high density about $34{\sim}69%$. Using fractal dimension and density, it would be possible to quantify the tidal channel development in association with surface characteristics.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.22-24
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• 2007

Waterline extraction is the one of widely used methods for studying changes in tidal flat environment and coastlines using multi-temporal optical images such as Landsat TM and Landsat ETM+. High dynamics of tidal currents and land reclamation which accelerate sedimentation and/or erosion cause waterline change in tidal flats. The amount of sediment deposited or eroded can be evaluated by precisely estimating waterline changes in tidal flats. The objective of this study is to detect the change of waterlines during 17 years and analyze the trends of erosion and sedimentation in the study areas. The Ganghwado tidal flat on the west coast of the Korean Peninsula was selected. The study area is famous for high dynamics of tidal currents and vast tidal flats. Land reclamation which has been carried out on a large scale is also considered as one of elements that have accelerated the environmental changes in this tidal flat. In this study, we acquired 26 waterlines from Landsat TM and Landsat ETM+ images. We extracted the waterline from each satellite image to generate a digital elevation map (DEM) which was used for reference and to compare with the other waterline which was extracted from DEM having a same tide. The result of comparison well depicted the areas of dominant sedimentation and erosion, and general trends of sedimentation and erosion according to sub-regions are also revealed during the investigation time. Results showed that erosion during a decade was dominant at the west of the Southern Ganghwado tidal flat, while sedimentation was dominant at the wide channel between the Southern Ganghwado tidal flat and the Yeongjongdo tidal flat. This area has been commonly affected by high currents and sedimentation energy. Although we were not able to verify the accuracy of the waterline changes, this result clearly showed the waterline change and therefore, the waterline extraction method used in this study has proven as an effective tool for long term tidal change estimation.

• Land and Housing Review
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• v.3 no.1
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• pp.97-109
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• 2012

For the design of underpass structures, -1.0m(G.L) ground water level guideline for the design of railway, subway, utility tunnel etc, is still being used in Korea. As a result, the underpass structure can be forced by buoyancy, and therefore the in-situ buoyancy anchor method is usually being applied to prevent the uplifting force. For the Yeongjongdo sky city project, the drainage method was applied to remove the buoyancy force. In this study we estimate the efficiency and safety of the applied design and propose the detailed guidelines for standard design and maintenance of the guided drainage technique. Especially, the auxiliary pumping well was operated to maintain the ground water level around the underpass. In the study site, the applied guided drainage method has advantages in both engineering and economic aspects.