• Environmental Engineering Research
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• v.25 no.1
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• pp.123-128
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• 2020

Non-point source pollutant load reductions were calculated using the Hydrologic Simulation Program-Fortran (HSPF) model under the assumption that landuse pattern was changed according to land purchases. Upon the simulation of non-point pollutant and areas with high land purchase ratios to select a buffer zone, the Namgang dam Reach 11, Imha dam Reach 10, and the Reach 136 watershed of the main river were found to rank high for the construction of buffer zones. Assuming that the forms of the purchased lands were changed to wetlands, biological oxygen demand (BOD) loads were changed through the HSPF model. No changes of BOD were present in the Namgang dam and the Imha dam watersheds. BOD loads in Reach 136 according to landuse change were analyzed through a flow duration analysis based on the total maximum daily loads of the United States. The flow duration analyses undertaken to examine changes in BOD of main river Reach 136 watershed indicated a shift of 0.64 kg/d from 3.16 to 2.52 during high flow. The change of BOD under the conditions of moist, mid-range and dry were 11.9%, 9% and 4.5%. At the low flow condition, the variation range in the BOD load was from 0.58 kg/d to 0.41 kg/d.

• Journal of the Korean Geophysical Society
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• v.8 no.3
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• pp.145-152
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• 2005

216 groundwater samples for inorganic constituents and 168 samples for VOCs in the Ulsan urban ares and analyzed to relate groundwater chemistry to four land use zones, residence․commercial, industrial, agricultural, and forestry. In general, Na and Cl concentrations in groundwater were high in residence․commercial zone near Taehwa river due to residual saline. Although NO3 contents is high in agricultural zone and VOCs content is high in industrial zone, it seems difficult to relate groundwater pollution to land use zone. Even though groundwater pollution of the area is still low, continuous monitoring is necessary because the city is expanding.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2004.11a
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• pp.189-194
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• 2004

Owing to the mass-housing policies of high-density and high-rise, the residential environments in Korea have come to be uniform and monotonous. Nevertheless, the design competitions introduced for the first time in 1980s have Played significant roles in developing the fresh ideas and concepts in housing design. And in our country, the land of the gradient $0-9^{\circ}$ that is able to plan as level sites come up to 32.5% of the total land and the land of the gradient $10-29^{\circ}$that should be designed by considering the characteristics of the sloping sites is 53.2% of the whole. For that reason, the development of the apartment housing in the sloping site has been done largely to solve the issues associated with the scarcity of the land. Therefore, it is very meaningful job to see the various design methods on the basis of the characteristics of the sites, particularly gradient, by analyzing the prizewinners in the design competitions. In this context, the research analyzed the works that won the design competition after 1990, and organized the types of the block plans and the design characteristics applied in our residence housing. Secondarily, it classified that types by the gradient and analyzed statistically and compared the numerical value.

• Atmosphere
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• v.22 no.3
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• pp.357-365
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• 2012

High spatio-temporal resolution hydrologic components can give important information to monitor natural disaster. The objective of this study is to create high spatial-temporal resolution gridded hydrologic components using TOPLATS distributed land surface model and evaluate their accuracy. For this, Andong dam basin is selected as study area and TOPLATS model is constructed to create hourly simulated values in every $1{\times}1km^2$ cell size. The observed inflow at Andong dam and soil moisture at Andong AWS site are collected to directly evaluate the simulated one. RMSEs of monthly simulated flow for calibration (2003~2006) and verification (2007~2009) periods show 36.87 mm and 32.41 mm, respectively. The hourly simulated soil moisture in the cell located Andong observation site for 2009 is well fitted with observed one at -50 cm. From this results, the cell based hydrologic components using TOPLATS distributed land surface model show to reasonably represent the real hydrologic condition in the field. Therefore the model driven hydrologic information can be used to analyze local water balance and monitor natural disaster caused by the severe weather.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.10a
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• pp.46-55
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• 2006

There are many kinds of braced cut wall methods as the sheet pile, SCW, CIP and slurry wall which is adoptable for a deep excavation construction in a coastal filled land. The braced cut wall which has a strong stiffness is very stable but it has the weak point that the construction cost is high. Thus when a braced cut wall is designed, the geotechnical engineers choose the braced cut wall which has more safe and economic in the consideration of surrounding buildings near the construction site. Especially, when the sheet pile method as a braced cut wall is cheesed, the layer order and consistence of a coastal deposit stratum are considered and the pile driving method is also considered. This paper introduces the case that the originally box-type sheet pile wall was changed to U-type and high strength material after the pilot test at the subway construction site in a coastal filled land. This paper also introduces the case that the sheet pile's driving method was changed to special method in the section of the temporary coffer dam which had made when the present coastal filled land was formed.

• Proceedings of the KSRS Conference
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• v.2
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• pp.647-650
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• 2006

Compact Airborne Spectrographic Imager (CASI) hyperspectral imagery was acquired over the Little Miami River Watershed (1756 square miles) in Ohio, U.S.A., which is one of the largest hyperspectral image acquisition. For the development of a 4m-resolution land cover dataset, a hierarchical approach was employed using two different classification algorithms: 'Image Object Segmentation' for level-1 and 'Spectral Angle Mapper' for level-2. This classification scheme was developed to overcome the spectral inseparability of urban and rural features and to deal with radiometric distortions due to cross-track illumination. The land cover class members were lentic, lotic, forest, corn, soybean, wheat, dry herbaceous, grass, urban barren, rural barren, urban/built, and unclassified. The final phase of processing was completed after an extensive Quality Assurance and Quality Control (QA/QC) phase. With respect to the eleven land cover class members, the overall accuracy with a total of 902 reference points was 83.9% at 4m resolution. The dataset is available for public research, and applications of this product will represent an improvement over more commonly utilized data of coarser spatial resolution such as National Land Cover Data (NLCD).

• Journal of Korean Society for Quality Management
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• v.45 no.3
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• pp.327-333
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• 2017

Purpose: The purpose of this study is to research to protect to loss of chrome-plating of small arms barrel on high temperature in order to extend its life expectency. Methods: The reason why chrome-plating dropped out is main material is weak from heat. Therfore, to make barrel of small arms have higher heat-resistant property, nitriding for barrel before chrome-plating is needed and test of that barrel was handled to improve it. Results: Nitriding before chrome-plating is useful to protect to chrome-plating loss on high temperature. Conclusion: To protect loss of chome-plating of small arms barrel during on firing, pre-nitriding on barrel is effective finally it leads to extend to barrel's life expectency.

• Land and Housing Review
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• v.11 no.2
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• pp.87-94
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• 2020

Offshore renewable energy resources are attractive alternatives in addressing the nation's clean energy policies because of the high demand for electricity in the coastal region. As a large portion of potential resources is in deep and farther water, economically competitive floating systems have been developed. Despite the advancement of floating technologies, the high capital cost remains a primary barrier to go ahead offshore renewable energy projects. The dynamically installed piles (DIPs) have been considered one of the most economical pile concepts due to their simple installation method, resulting in cost and time-saving. Nevertheless, applications to real fields are limited because of uncertainties and underestimated load capacity. Thus, this study suggests the appropriate analytical approach to estimate the inclined load capacity of the DIPs by using the upper bound plastic limit analysis (PLA) method. The validity of the PLA under several conditions is demonstrated through comparison to the finite element (FE) method. The PLA was performed to understand how flukes, soil profiles, and load inclinations can affect the inclined load capacity and to provide reliable evaluations of the total resistance of the DIPs. The studies show that PLA can be a useful framework for evaluating the inclined load capacity of the DIPs under undrained conditions.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.2
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• pp.59-71
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• 2019

This study was conducted to prioritize land purchase in Hwapocheon wetland protection area by reflecting the conservation value of wetlands considering HSI(Habitat Suitability Index) for flagship species. As a result of this study, the flagship species, Oriental White Stork and Been Goose, which can represent the Hwapocheon wetland protection area, were selected through selection criteria and expert feedback. Based on the habitat requirements of the selected flagship species, SI(Suitability Index) for the flagship species was reviewed and the conservation value of wetlands was assessed. The conservation value of the wetlands was divided into five grades from very high to very low. The areas with high conservation value were mainly distributed around wetlands and waters in upstream and downstream of Hwapocheon wetland protection area. The land purchase priorities were divided into five grades by overlapping the thematic maps of the conservation value of wetlands, the economics, and the urgency of restoration. The arable lands which can disrupt wetland ecosystems are analyzed as priority areas where priority purchasing is required. Relatively well-preserved wetlands and areas have low land purchase priorities. This study is meaningful in that biodiversity is considered in land purchase priorities.

• Korean Journal of Soil Science and Fertilizer
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• v.51 no.1
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• pp.50-60
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• 2018

This study was to evaluate the effect of organic amendments incorporation on soil properties and plant growth under two different soil salinity levels and various cultivated crops at Saemangeum reclaimed tidal land for three years from 2012 to 2014. The soil texture of the experimental site was sandy loam. Four different crops, sesbania (Sesbania grandiflora), sorghum-sudangrass hybrid (Sorghum bicolor-Sorghum sudanense), rice (Oryza sativa L.) and barley (Hordeum vulgare) were cultivated at low (< $1dS\;m^{-1}$) and high (> $4dS\;m^{-1}$) soil salinity levels. The soil salinity was significantly lowered at the rice cultivation site compared to continuous upland crops cultivation site in high soil salinity level. But the soil salinity was increased as cultivating sesbania coutinuously in low soil salinity level. The soil organic matter content was increased with the incorporation of straw at the continuous site of rice and barley, and the average of soil organic matter was increased by $0.9g\;kg^{-1}$ per year which was effective in soil aggregate formation. The highest biomass yield plot was found in barley (high salinity level) and sesbania (low salinity level) cultivation site, respectively. Our research indicates that rice cultivation in paddy field with high salinity level was effective in lowering soil salinity and sesbania cultivation was useful to biomass production at upland with low salinity. In conclusion, soil salinity and organic matter content should be considered for multiple land use in newly reclaimed tidal land.