• Journal of Korean Society for Atmospheric Environment
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• v.6 no.2
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• pp.155-160
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• 1990

During the period from Mar. 1985 to Feb. 1988, airborne particulate matters were collected and size fractionated by the ANdersen high volume air sampler in Seoul. The concentrations of several heavy metals (Pb, Cu, Zn, Fe, Mn) and benzo(a)pyrene were determined to investigate the size distributions and seasonal variations. And with respect to seven components in the total suspended particulate (TSP), the factor analysis was performed for three groups such as the coarse particles (> 2 $\mu$m), fine particles (< $\mu$m) and TSP. As a result of factor analysis by using the varimax method, the chemical components in the TSP were able to characterize with two principal factors. The first factor, F1 was considered to be a factor indicating the contribution of natural sources and the second factor, F2 was a factor indicating the degree of artificial sources. Each components in the TSP was divided into two main groups of components originated from soil and/or road dust and pollutants originated from automobiles and/or human work.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.241-246
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• 2005

Doam watershed is located at alpine areas in the Kangwon province. The annual average precipitation, including snow accumulation during the winter, at the Doam watershed is significantly higher than other areas. Thus, pollutant laden runoff and sediment discharge from the alpine agricultural fields are causing water quality degradation at the Doam watershed. To estimate soil erosion from the agricultural fields, the Universal Soil Loss Equation (USLE) has been widely used because of its simplicity to use. The USLE rainfall erosivity (R) factor is responsible for impacts of rainfall on soil erosion. Thus, use of constant R factor for the Doam watershed cannot reflect variations in precipitation patterns, consequently soil erosion estimation. In the early spring at the Doam watershed, the stream flow increases because of snow melt, which results in erosion of loosened soil experiencing freezing and thaw during the winter. However, the USLE model cannot consider the impacts on soil erosion of freezing and thaw of the soil. Also, it cannot simulate temporal changes in USLE input parameters. Thus, the Soil and Water Assessment Tool (SWAT) model was investigated for its applicability to estimate soil erosion at the Doam watershed, instead of the widely used USLE model. The SWAT hydrology and erosion/sediment components were validated after calibration of the hydrologic component. The $R^2$ and Nash-Sutcliffe coefficient values are higher enough, thus it was found the SWAT model can be efficiently used to simulate hydrology and sediment yield at the Doam watershed. The effects of snow melt on SWAT estimated stream flow and sediment were investigated using long-term precipitation and temperature data at the Doam watershed. It was found significant amount of flow and sediment in the spring are contributed by melting snow accumulated during the winter. Thus, it is recommend that the SWAT model capable of simulating snow melt and long-term weather data needs to be used in estimating soil erosion at alpine agricultural land instead of the USLE model for successful soil erosion management at the Doam watershed.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.984-999
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• 2010

A long-term field demonstration experiment of selected stabilization method to reduce the heavy metal mobility in farmland soil contaminated by heavy metals around abandoned mine site was conducted. Field demonstration experiments were established on the contaminated farmland with the wooden plate(thickness=1cm) which dimension were width=200cm, Length=200cm, height=80cm and filled with treated soil, which was mixed with lime stone and steel refining slag except on control plot. Soil samples in the plots were collected and analyzed during the experiment period(2008. 2~2008. 8) after the installation of the plots. Field demonstration experiments results showed that the application ratio of lime stone 5% was effective for immobilizing heavy metal components in contaminated farmland soil.

• Geomechanics and Engineering
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• v.20 no.5
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• pp.433-445
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• 2020

A new code, called PRaFULL (Piled Raft Foundation Under Lateral Load), was developed for the analysis of laterally loaded Combined Pile Raft Foundation (CPRF). The proposed code considers the contribution offered by the raft-soil contact and the interactions between all the CPRF system components. The nonlinear behaviour of the reinforced concrete pile and the soil are accounted. As shallower soil layers are of great relevance in the lateral response of a pile foundation, PRaFULL includes the possibility to consider layered soil profiles with appropriate properties. The shadowing effect on the ultimate soil pressure is accounted, when dealing with pile groups, as proposed by the Strain Wedge Model. PRaFULL BEM code obviously requires less computational resources compared to FEM (Finite Element Method) or FDM (Finite Difference Method) codes. The proposed code was validated in the linear elastic range by comparisons with the code APRAF (Analysis of Piled Raft Foundations). The reliability of the procedure to predict piled raft performance was then verified in nonlinear range by comparisons with both centrifuge tests and computer code PRAB.

• Journal of Plant Biology
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• v.7 no.2
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• pp.1-8
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• 1964

Cha, Jong Whan (Dept. of Biology, Graduate School, Dong Kuk Univ.) The changes of chemical properties of forest soils in dry and wet seasons. Kor. Jour. Bot. VII(2): 1-8, 1964. Soil selected for the present investigation was collected from a mountain of the Forestry Experiment Station of the vicinity of Seoul. The forest communities studied were three forest and a unplanted soils. The soil samples were obtained from each forest type during dry and wet seasons. And these samples were collected from four horizons of all communities respectively. It was showed that exchangeable hydrogen was increased by rainfall, and total exchangeable base decreased in the same way. The content of nitrogen is washed away by rainfall, especially ammonium nitrogen was highly significant between dry and wet season. On the contrary, organic matter and available phosphorus were of no significant difference between dry and wet seasons. The values of pH appeared a different response in dry and wet seasons according to the plant communities. The needle-leaved forest soils showed more acidity than the broad-leaved forest soils, and the least acidity in open places. All nutrients in soil studied gradually decreased down the profiles. According to statistical analyses of the soil components among all soil horizons, total exchangeable bases in wet season indicated only significant at 1%. Exchangeable hydrogen and organic matter of the soil in dry season was particularly very low with increased depth in the profile. The fertility level of most forested soils selected for the present investigation is low according to chemical tests for available nutrient elements.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.209-215
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• 2014

The purpose of this study is identify chemical changes in yield components of soil using organic fertilizer for cultivating rice and establish reasonable methods of fertilization. In chemical change, comparing the control plot, the soil using organic fertilizer consistently for three years for cultivating rice showed an increase in pH and available phosphate in the experiment plots provided by the organic fertilizer, increase in spikelet number and 1000 grain weight in terms of yield components, and increase in yield in the three-year experiment plots. As for the quality of brown rice, the rate of head rice showed no difference when compared to that of the control plots. As for protein content, it was difficult to identify a statistical significance between the control plots and the experiment plots in 2009, but since 2010, the protein content of the experiment plots has been lower than that of the control plot, indicating that fertilization of organic fertilizer was effective in terms of rice quality. In conclusion, long-term use of organic fertilizer improved the chemical properties of soil and increased yield when compared to practical fertilization. Reasonable fertilization was identified to fertilize the nitrogen component of organic fertilizer to be a level of 12kg/10a.

• Journal of Internet Computing and Services
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• v.9 no.3
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• pp.129-139
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• 2008

This paper proposes a Ubiquitous Greenhouse Management System (UGMS) based on USN(Ubiquitous Sensor Network) which can be real-time monitoring and controlling of greenhouse's facilities by collecting environment and soil information with environment and soil sensors, and CCTV camera. The existing systems were controlled simply by temperature. Also, it was possible to monitor only at control room in a greenhouse. For solving problems of the exiting system, our system can remotely monitor and control greenhouse by considering environment information. The detail components are as follows. The system includes the sensor manager and the CCTV manager to gather and manage greenhouse information with soil and the environment sensors, and camera. Also the system has the greenhouse database storing greenhouse information and the greenhouse server transmitting greenhouse information to the GUI and controlling greenhouse. Finally, the GUI showing greenhouse condition to users exists in our system. To verify the executability of the UGMS, after developing the greenhouse model, we confirmed that our system could monitor and control the greenhouse condition at remote GUI by applying the UGMS's components to the model.

• Korean Journal of Agricultural Science
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• v.37 no.1
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• pp.73-80
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• 2010

Functional and nutritional components of 7 cultivars of Chinese cabbage (CC; Brassica rapa subspecies campestris) from China were analyzed to compare the effects of soil pH (6.9 vs. 7.6). The CC grew on the soil of pH6.9 (CC-6.9) contained significantly increased amounts (2.3~4-fold) of pectin, crude protein, vitamin C and vitamin E compared to the control. The contents of ash and minerals (Ca, Fe, Na, Zn, K and Mn) were also significantly increased in CC-6.9. However, CC-6.9 contained 16-75% lower contents of reducing sugars, cellulose and crude fat than CC-7.6. CC-7.6 contained more glucosinolates than CC-6.9; gluconasturtiin (20.68 vs. 0.84 $nmol{\cdot}g^{-1}$ wet wt) and gluconapin (202.55 vs. 0.15 $nmol{\cdot}g^{-1}$ wet wt). In conclusion, CC-6.9 had an improved texture (high pectin and low cellulose) and nutritional value (high in protein, Ca, Fe, Zn, vitamin C, and E), whereas CC-7.6 had better taste (high in reducing sugars) and anticancer functionality (high in glucosinolates).

• Korean Journal of Organic Agriculture
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• v.16 no.4
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• pp.455-469
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• 2008

A research was conducted to investigate the effect of treatment of woody charred materials such as wood vinegar, charcoal, and mixture of wood vinegar and charcoal on the growth and components of tomato and chinese cabbage. The effect of treatment of woody charred materials on the growth and components of tomato the research findings are as follows. The total number of soil microorganisms increased in the groups treated with woody charred materials compared with the control. The fruit number, fruit length, fruit diameter, fruit weight, hardness and sugar contents of tomato did not show significant difference in all plots treated with woody charred materials, but the plot treated with wood vinegar + charcoal showed relatively higher values in general. Vitamin C contents were shown higher in the plots treated with woody charred materials than the control, and among the treatment plots. The effect of treatment of woody charred materials on the growth and components of chinese cabbage the research findings are as follows. The soil chemical components did not change before and after the treatment of woody charred materials. The total number of soil microorganisms increased in the treatment plots compared with the control, The leaf length, leaf width, inner leaf number, plant weight, and head weight of Chinese cabbage treated with woody charred materials were in general larger than the control. Among the treatment plots, the plot treated with wood vinegar + charcoal showed slightly higher values. The contents of minerals in chinese cabbage such as Ca, Fe, K, Mg and Mn were higher in the treatment plots than the control.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.1
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• pp.110-134
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• 1977

Effects of phosphorus, potassium and calcium applications on root activity and agronomic characters of paddy rice were studied in submerged paddy soil on which starch was applied to accelerate soil reduction and production of toxic substance during 1971～1973. Root activity at heading date was decreased in reduction accelerated soil by starch application. Effect of calcium application on root activity was differed along soil conditions, phosphorus or potassium levels. Single effects of phosphorus or potassium application were not significant on every observed characters. Calcium application when phosphorus or potassium was not used as basal but used as top dressing increased yield and yield components, especially filled grain ratio. Effect of calcium application along soil conditions was differed on agronomic characters, but calcium application with phosphorus or potassium was more effective to increase yield components and grain yield. Sufficient application of phosphorus, potassium and calcium could improve the nutritional situation of rice plant for panicle development and grain maturity in reduction accelerated paddy soil in which poor growing of rice plant after panicle formation is anticipated by the production of toxic substance from soil.