• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1998.11a
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• pp.232-235
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• 1998

Air sparging system is a kind of in-situ bioremediation method in the contaminated ground water. When Air sparging, the both of water circulation and oxygen transfer happend in the same time. The hydraulic differential head is zero at the middle height of well, is negative below the height and is possitive above the height. Hydroraulic head gradient is proportioned to air superficial velocity in the well. But over 24m/min of the superficial velocity, the hydraulic head gradient increase little.

• 한국생물공학회:학술대회논문집
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• 2004.07a
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• pp.35-45
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• 2004

This paper reviewed effects of global climatic changes on wetland biogeochemistry, Wetlands play key roles in global as well as local material cycle, which includes carbon sequestration, $CH_4$ emission and DOC leaching, Increased air temperature, elevated $CO_2$ levels and changed precipitation patterns are believed to affect those processes substantially by modifying oxygen supply, carbon sources, and decomposition rates. For example, elevated $CO_2$ may increase $CH_4$ emission as well as DOC leaching from wetlands. In addition, interactions of multiple effects warrant further investigation.

• Journal of Engineering Education Research
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• v.17 no.4
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• pp.25-32
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• 2014

Following the collaborator meetings report towards practical engineering education at universities(June 2010), the Pioneering University Reform Project supported by The Ministry of Education, Culture, Sports, Science and Technology(MEXT) of Japan solicited opinions from industry, professional associations, and academia on the goals of the individual fields, as well as common goals, that could be adaptable and applicable for a broad range of universities and curricula. This paper gives an overview of two surveys that were conducted, as well as a summary of the mechanical engineering goals as an example of the individual fields.

• The Journal of Engineering Geology
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• v.18 no.1
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• pp.69-81
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• 2008

Landslide researches are divided to a method of interrelationship for various factors, method of predicting landslide possibility, and method of estimating landslide risk which are occurring landslides in the natural slope. Most of landslides occurred in natural slope are caused by a heavy rainfall in summer season. Weathered soil layer located in upper side of rock mass was occurred. As well as, they are announced to have an influence to geometry, geology, soil characteristics, and precipitation in the natural slope. In order to investigate and interpret the variety of landslides from field investigation to risk analysis, landslide analysis process due to geotechnical and geological opinions are systematically demanded. In this research, the study area is located in Macheon area, Gyeongsangnam-do and performed the landslide investigation. From the results of landslide investigation and analysis, optimized standard model based on natural landslide is proposed to high technical method of landslide investigation and interpretation.

• Journal of Environmental Health Sciences
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• v.31 no.2 s.83
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• pp.134-146
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• 2005

Environmental monitoring system has been adopted and supplemented as inspection measures for the quantitative and qualitative changes of environmental impact assessment (EIA). This study compares the results of environmental impact assessment with the results of post-environmental investigation using a correction and principal component analysis (PCA) in the housing development project. Correlation analysis showed that most of air quality variables including TSP, $PM_{10},\;NO_2$, CO were linearly correlated with each other in the environmental impact assessment and the post-environmental investigation. In the water quality, pH and BOD were well correlated with the DO and SS, respectively. As a result of correlation analysis in the noise and vibration, noise in day and night and vibration in day and night were related to each other between EIA and the post-environmental investigation. From the results of analysis of soil, Cu with Cd, Cu with Pb, and Cd with Pb were related to each other in EIA. Principal component analysis (PCA) showed a powerful pattern recognition that had attempted to explain the variance of a large dataset of inter-correlated variable with a smaller set of independent variables (principal components). Principal component (PC1) and principal component (PC2) were obtained with eigenvalues> 1 summing almost $90\%$ of the total variance in the all of the items(air, water, noise, vibration and soil) in EIA and post-environmental investigation.

• Journal of Soil and Groundwater Environment
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• v.15 no.4
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• pp.1-12
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• 2010

Well production by a riverbank filtration facility with multi-radial collector well systems in Jeungsan-ri, Changnyeong gun, Korea was evaluated. In this study, the drawdown at collector wells due to pumping and groundwater inflow rates along the horizontal arms of the collector wells were computed through numerical simulations. Sensitivities of the well production to hydraulic conductivity and well flow coefficient, which represents the resistance to the flow from the aquifer to the horizontal arms, were analyzed. Simulation results showed that, with given proposed pumping rate conditions, the drawdown in the caisson exceeded maximum drawdown constraints in the study site and the adjustment of the pumping rate at each well is needed. The drawdown is affected by the hydraulic conductivity of the main aquifer and the well flow coefficient, which means the profound field investigation of the study site is needed to accurately estimate the efficiency of riverbank filtration through radial collector wells.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.265-277
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• 2003

• Journal of the Korean Society of Industry Convergence
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• v.5 no.1
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• pp.65-74
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• 2002

This paper intends to investigate such effects through experiments. The contents of the investigation are effects of position of repeated loading and unloading, passing frequency. For the purpose of the investigation an experimental load-deflection system is developed and the system is possible to measure deflection of the wall and earth pressure due to different size of strip loading and cyclic loading. The findings from the experiments are as follows: 1. As repeated loading approaches to the wall, the measured horizontal residual earth pressure agrees well with Rowe's empirical formula, while as the loading is far from the wall the earth pressure consists with Boussinesq's and Spangler's formulas. Also it is found that below 0.6m depth from ground surface the effects of repeated loading can be nearly neglected. 2. From comparison analyses of earth pressure theories and experimental results, a reagression equation is suggested herein, and earth pressure at any depth and maximum earth pressure due to cyclic loading can be estimated from the equation.

• Human Ecology Research
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• v.55 no.3
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• pp.249-261
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• 2017

This study grasps the structural relationships between temperament, social support, and school adjustment by adolescents as well as investigates the mediating effect of positive psychological capital from relationships between temperament, social support, and school adjustment. Participants in this study consisted of 763 students in the second grade of five middle schools. Productive correlation analysis were conducted on data collected for this study using PASW statistics ver. 18.0 program; in addition, structural equation modeling analysis was conducted using AMOS ver. 18.0 program. The main findings are as follows. Paths appeared in different ways according to the investigation of mediating effect of positive psychological capital under the impact of temperament and social support on school adjustment of adolescents. Investigation showed that harm avoidance temperament had a statistically significant indirect effect on school adjustment with a medium of positive psychological capital. Novelty seeking temperament and persistence temperament had a direct impact on the school adjustment of adolescents; however, it appeared to also indicate an indirect impact through a medium of positive psychological capital. Social support seemed to indicate a direct impact on school adjustment of adolescents as well as an indirect impact through a medium of positive psychological capital. This study provides basic data to help in the school adjustment of adolescents using personal, environmental, and psychological variables that proves the importance of positive psychological capital in adolescence.

• International Journal of Automotive Technology
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• v.8 no.4
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• pp.483-491
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• 2007

A closed form solution of a composite mechanics system is performed for the investigation of elastic-plastic behavior in order to predict fiber stresses, fiber/matrix interfacial shear stresses, and matrix yielding behavior in short fiber reinforced metal matrix composites. The model is based on a theoretical development that considers the stress concentration between fiber ends and the propagation of matrix plasticity and is compared with the results of a conventional shear lag model as well as a modified shear lag model. For the region of matrix plasticity, slip mechanisms between the fiber and matrix which normally occur at the interface are taken into account for the derivation. Results of predicted stresses for the small-scale yielding as well as the large-scale yielding in the matrix are compared with other theories. The effects of fiber aspect ratio are also evaluated for the internal elastic-plastic stress field. It is found that the incorporation of strong fibers results in substantial improvements in composite strength relative to the fiber/matrix interfacial shear stresses, but can produce earlier matrix yielding because of intensified stress concentration effects. It is also found that the present model can be applied to investigate the stress transfer mechanism between the elastic fiber and the elastic-plastic matrix, such as in short fiber reinforced metal matrix composites.