• Journal of Soil and Groundwater Environment
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• v.22 no.6
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• pp.94-103
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• 2017

Surface soil is one of the most important resources that have many functions for human needs such as conservation of water resource, purification of contaminated materials, and productivity of food or energy. However, the surface soil is a limited resource that cannot be recovered readily for a long time once it is lost by erosion. In Korea, the Ministry of Environment enacted the notification on the investigation of surface soil erosion and corresponding countermeasures. As the results, database of soil quality assess criteria (biomass, groundwater recharge, habitat, carbon storage, buffer, and soil loss) was established, and the web-based system that can evaluate surface soil conditions was developed. However, non-experts have difficulties in using the system because the system requires in-depth knowledge about soil qualities. In this study, the Web Geographic Information System (GIS) watershed-based surface soil information system was developed to improve usability of the system and accessibility of soil quaility database. The system provides the current condition of surface soil characteristics and GIS-based soil data at selected locations. The users are able to download soil quality data in different districts, watersheds, and special regions allocated by TauDEM module. The system developed in this study would valuable surface soil information for studies of soil quality and its environmental effects, and thereby contributing to establishing more appropriate and robust soil conservation laws.

• Journal of Biosystems Engineering
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• v.27 no.1
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• pp.39-44
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• 2002

In order to obtain the information of bio-environment control, the thermal characteristics of soil in the greenhouse heated by the heat pump and latent heat storage system were experimentally analyzed. The experimental systems were composed of the greenhouse with a heat pump and a latent heat storage system (system I), the greenhouse with a heat pump (system II), the greenhouse with a latent heat storage system (system III), and the greenhouse without auxiliary heating system (system IV). The thermal characteristics experimentally analyzed in each system were temperature of soil layers, soil heat storage and release, soil heat capacity and soil heat storage ratio. The results could be summarized as follows. 1. Time to reach the highest temperature at 20cm deep in soil layers of the crop routs in case of system I was shown to be delayed by 6 hours in comparison to the time of the highest temperature at the soil surface. 2. In the clear winter days, the stored heat capacity values fur the system I and the system II were shown to be 22.3% and 11.0% higher than the released heat capacity respectively, and the stored heat capacity values for the system III and the system IV were shown to be 6.2% and 29.6% lower than the released heat capacity respectively This confirms that the system I provided the best heat storage effect. j. The heat quantity values stored or released were shown to be highest at 5 cm depth of soil layers. And it was reduced with increasing of depth of soil layers until 20 cm and was not changed under the soil layer of 20 cm depth. 4. The heat absorption rates of soil, the ratio between supplied and stored heat energy, fur both the system I and system II were lower than 23%.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2000.04a
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• pp.120-129
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• 2000

As structure-soil interaction analysis for the seismic analysis of structures requires a nonlinear analysis of a structure-soil system considering the inelastic characteristics of soil layers nonlinear analyses of the foundation-soil system with the horizontal excitation were performed considering the nonlinear soil conditions for the nonlinear seismic analysis of structures. Stiff soil profile of SD and soft soil profile of SE specified in UBC were considered for the soil layers of a foundation and Ramberg-Osgood model was assumed for the nonlinear characteristics of soil layers. Studies on the changes of dynamci stiffnesses and damping rations of surface and embedded foundations depending on foundation size soil layer depth and piles were performed to investigate the effects of the nonlinear soil layer on the horizontal and rotational dynamic stiffnesses and damping ratios of the foundation-soil system According to the study results nonlinear prperties of a soil laryer decreeased horizontal and rotational linear stiffnesses and increased damping ratios largely Effects of foundation size soil layer depth and piles were also significant suggesting the necessity of nonlinear seismic analyses of structures.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.1081-1086
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• 2010

The general soil nailing support system may result in excessive deformations particularly in an excavation zone of the existing weak subsoils. Pretensioning the soil nails then, could play important roles to reduce deformations mainly in part of the nailed-soil excavation system as well as to improve local stability. Morever, soil nails are installed underneath roads, underground structures, and subway structures, thereby resulting in difficulties in nail remval after completion of temporary soil nailed walls. Hence, to date, in order to solve the technical difficulties and avoid legal issues related to the construction of soil nails underneath the surrounding areas and structures, the removable soil nailing system has been developed and used. But, Therefore, a new soil nailing technique called Removable Post-tensioned Soil Nailing(RPTN) system has been developed in the current study. In this study, an investigation of the RPTN system has been conducted by carrying out field measurement. Hence, the RPTN system can reduce ground displacement and enhance stability of the soil nailed walls.

• Agricultural and Biosystems Engineering
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• v.6 no.1
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• pp.15-21
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• 2005

This study was conducted to develop a nondestructive grouping system for soil organic matter using visible (VIS) and near infrared (NIR) spectroscopic method. The artificial light was irradiated on the cut soil surface at 15 to 20 cm depths to reduce the errors of light at open field. The reflectance energy from the cut soil surface was measured to group the soil organic matter using VIS/NIR light sensor with narrow band pass filter. From reflectance spectra of soil samples, the sensitive wavelengths for measuring the soil organic matter were selected and compared to previous research results. The grouping system for soil organic matter consisted of light sensor with band pass filter measuring the reflectance energy of the cut soil surface, global positing system (GPS), analog-to-digital (AD) converter, computer and operating software. The regression models to predict the soil organic matter were developed and evaluated. From field test, the accuracies of the developed light sensor system were 81.3% for five-stage grouping of the soil organic matters and 91.0% for three-stages grouping of the soil organic matters, respectively. It could be possible to support the decision making for variable rate applications with the developed grouping system for soil organic matter in precision agriculture.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.6
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• pp.81-90
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• 2008

Recently, geofiber(polyester) reinforced soil was added on soil-seed mixture spray to control erosion and to improve vegetation growth on rocky slope sites. This research was conducted to compare vegetation effects and soil hardness on three types of soil-seed mixture spray on stone gabion river bank [A type : soil-seed mixture spray underlying 30cm thick sand with geofiber(geofiber reinforced soil system), B type : soil-seed mixture spray underlying 30cm thick sand without geofiber, C type : soil-seed mixture spray]. Evaluation were made concerning vegetation coverage, soil hardness and moisture content. The results of this study showed that A type system was effective for the growth of vegetation and soil hardness when compareed to B type and C type. A type and B type showed higher covering rate than C type on stone gabion river bank, and especially A type showed the highest covering rate. Soil hardness and water content were high on A type vegetation system compared to B type and C type. We noted that high soil hardness and high moisture content with geofiber(geofiber reinforced soil system) were effective both to control erosion from water current impact and to be high coverage and species of vegetation on stone gabion river bank.

• Coupled systems mechanics
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• v.7 no.4
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• pp.395-406
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• 2018

This paper proposes a linear damping model of tire-soil system using semi-empirical method. A test rig was designed and developed to measure the vertical equivalent linear damping ratio of tire only and tire-soil system using Free-Vibration Logarithmic Decay Method. The test was performed with two kinds of tractor tires using a combination of five inflation pressure levels, two soil depths and four soil moisture contents in the paddy soil. The results revealed that the linear damping ratio of tires increased with decreasing tire inflation pressure; the linear damping ratio of tire-soil system also increased with decreasing tire inflation pressure and increased with the increasing soil depth (observed at 80 and 120 mm). It also increased with a relative increase of soil moisture contents (observed at 37.9%, 48.8%, 66.7% and 77.4%). The results also indicated that the damping ratio of tire-soil system was higher than that of tire only. A linear damping model of tire-soil system is proposed as a damping model in parallel which is established based on experimental results and vibration theory. This model will have a great significance in study of tractor vibration.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.1014-1023
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• 2006

Soil nailing is a reinforcement method used for stabilizing excavated wall or slope. Due to its many advantages such as ease of construction and economical efficiency, use of soil nailing is increased. However, the soil nail can't trespass on the neighbor private land, which pays rent for use. For this reason, removable soil nailing system was developed. However, the removal rate of this system is just about $50\sim70%$. To solve this, the Fiber Reinforced Polymer (FRP) soil nailing system, which does not need to be removed and allows for the trespass on the private land, is developed. In this paper, through theoretical and experimental studies in laboratory and field, we evaluate the stability and behavior characteristics of the FRP nail system. Besides, numerical analyses using FLAC2D were performed for various soil conditions, where the simulations for pullout tests were carried out. As a result, compared with the conventional removable soil nailing system, the FRP soil nailing systems show similar behavior characteristics.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.3
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• pp.174-179
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• 2017

Soil parameters are required inputs to crop models, which estimate crop yield under a given environment condition. The Korean Soil Information System (KSIS), which provides detailed soil profile record of 390 soil series in the HTML (HyperText Markup Language) format, would be useful to prepare soil input files. Korean Soil Information System Processing Tool (KSISPT) was developed to aid generation of soil input data based on the KSIS database. Java was used to implement the tool that consists of a set of modules for parsing the HTML document of the KSIS, storing data required for preparing soil input file, calculating additional soil parameter, and writing soil input file to a local disk. Using the automated soil data preparation tool, about 940 soil input data were created for the DSSAT model and the ORYZA 2000 model, respectively. In combination with soil series distribution map at 30m resolution, spatial analysis of crop yield could be projected under climate change, which would help the development of adaptation strategies.

• Journal of Korean Society on Water Environment
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• v.31 no.6
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• pp.693-699
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• 2015

It has been known that torrential rainfall events have been occurring worldwide due to climate change. The accelerated soil erosion has caused negative impacts on water quality and ecosystem of receiving waterbodies. Since soil security issues have been arising in various areas of the world, intensive interests have been given to topsoil management in Korea. Thus in this study, Web GIS-based computing system of physical, chemical, and biological topsoil quality indices were developed. In this study, five soil quality maps at national scale and top soil erosion potential were prepared for evaluation of soil quality based on soil erosion potential. For this system, the open source Web GIS engine, OpenGeo, was used as core engine of the system. With this system, decision makers or related personnel in areas of soil erosion Best Management Practices (BMPs) would be able to find the most appropriate soil erosion BMPs based on soil erosion potential and soil quality at the area of interest. The Web GIS system would be efficiently used in decision making processes because of ease-of-use interface and scientific data used in this system. This Web GIS system would be efficiently used because this system could provide scientific knowledge to decision makers or stakeholders. Currently various BMP database are being built to be used as a decision support system in topsoil management and topsoil quality areas.