• Journal of Science Education
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• v.34 no.1
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• pp.93-104
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• 2010

The purpose of this study was to investigate the high school students' interests and and perceptions about the soil concepts. The data were obtained from 72 boys and 82 girls at a high school in Daegu area. The questionnaires were developed 8 questions for students' interest and 10 questions for students' understanding. The results of this study were as follows. In the examination of students' interest on the soil concepts, boys showed 3.2point(64.9%) out of 5point and girls showed 3.2point(64.6%) out of 5 point. Furthermore, a percentage of correct answers for understanding on the soil concepts was 47.4%. In detail, Boys had 48.2% and girls had 46.6%, boys showed higher understanding about soil concepts than girls. And students understood soil concepts by a visible side, to approach the soil concepts from a biological point of view, rather than a geologic one. Also high school students didn't think soil concepts to consist of minerals and rocks from a geologic point of view. Correlation between interest and understanding on the soil concepts was very weak by showing r=.170(p<.05).

• Journal of the Korean Society of Floral Art and Design
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• no.42
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• pp.37-62
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• 2020

The earth is a natural material that has natural healing power,,as a natural ingredient, it brings environmental friendliness, emotional. In this Research, for one of the methods to expand the benefits as a healing space, Construction of the Earth design and earth construction methods have been actively used for effectiveness of the Earth in the construction of the interior with the oriental medical clinic. By utilizing the concept of biophilic design as a healing environment design, symbolizing nature such as color, light, plants, flowers, and natural materials such as earth and wood was directed as oriental medicine interiors. In addition, the space was divided according to the movement of patients and used different Earth construction method to each of the space for the distinction and differentiation according to the characteristics of each space. At this time, the Earth was constructed with materials and finishing materials that meet the highest grade of HB (Healthy Building), an eco-friendly building material certification grade without additives, so that the interior and medical treatment concept can be done at the same time. By using Earth as the basis of elements in the construction, and the design of healing space, patient the concept of Biophillic as a healing environment design. This may serve as a technical, aesthetic, and cultural basis for constructing a healing space by Earth in the future-oriented alternative, it may lead to necessity of eco-friendly and ecological architecture, and it may be an opportunity to expand the application area of earth in architectural design.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.199-210
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• 2003

The development of strain localization within shear zones is frequently observed during soil deformation. In fact, the phenomenon appears to be more often the norm rather than the exception. Conceptually, any soil condition that renders negative work increment is prone to localization. In this study, a broad range of soil and loading conditions are investigated to test this criterion, including: dilative soil subjected to drained shear (standard case), contractive soil sheared under undrained conditions, cavitation in dilative soil in undrained shear, inhomogeneous soils, particle alignment in contractive soils made of platy particles, soils that experience particle crushing, and the shear of low-moisture and/or lightly cemented loose soils. Unique specimens and test procedures are designed to separately test each of these soil conditions in the laboratory According to experimental test results, soil specimens with post-peak strain softening behavior are prone to progressive failure, localization of deformations, and shear banding. The state of stress, the soil density, inherent mechanical and geometrical properties of soil particles, low water content, and heterogeneity can contribute to triggering strain localization. Considering all possible cases of localization, the best method to obtain the critical state line in the laboratory is to use contractive homogeneous specimens subjected to drained shear.

• Journal of the Korean Geotechnical Society
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• v.20 no.5
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• pp.27-35
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• 2004

The goal of this study is to investigate the feasibility of the reference state approach in determining the generalized soil-water characteristic curve that is essential fur characterization of unsaturated soil behavior. The soil-water characteristic curves are obtained from a number of specimens of fine-grained residual soils compacted with different void ratios. Based on the experimental test results, the feasibility of using the liquid limit state as the reference state for predicting the soil-water characteristic curve is verified. Finally, through the regression analysis of experimental data using the equation of Fredlund and Xing (1994), a reliable method is proposed to predict the generalized soil-water characteristic curve of fine-grained residual soils using the liquid limit state as the reference state.

• Korean Journal of Child Education & Care
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• v.17 no.4
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• pp.51-69
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• 2017

The purpose of this study is to derive educational meaning by analyzing 5-year-olds' activities process in soil-themed activities about 'soil' theme which was investigated by examination and teachers' reflective journals. For this, data of 20 children in 5-year-old class were collected and analyzed. As a result, firstly the value of children's pre-concept evaluation on soil theme was identified. Secondly, 'soil' theme was found to have a positive influence on children's feeling of wonder about nature and their ecological perspective taking ability. Thirdly, children could comprehensively investigate science education fields such as biology, ecology, and earth science in the process of investigating soil theme. Fourth, children came into interest in the process of understanding the relationship between soil and human through media. Lastly, children were found to compose scientific knowledge while investigating soil, through naturally using the method of inference.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.163-172
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• 1990

The filter criteria of geotextiles to prevent excessive loss of fine particles in cohesion-less soils are largely depend on the flow conditions of water in soil/geotextile systems. In the soil/geotextile system under uni-directional flow conditions, it is adequate to retain only the coarse soil fraction because a 'self-induced' soil filter layer may form in cohesionless soil adjacent to the geotextile. In alternating flow conditions, however, a complete soil filter layer within the soil will not form and thus the geotextile pores must be small enough to retain finer particles of the soil to be protected. Based on these concepts, theoretical filtration criteria of geotextiles are developed considering the flow conditions of water. To test the validity of these criteria, laboratory testing was carried out. This indicated that large losses of fine particles would result, especially at high hydraulic gradients, short periods and low vertical loads. The revised filtration criteria are proposed evaluating effect of various design factors.

• Journal of the Korean GEO-environmental Society
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• v.11 no.11
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• pp.47-54
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• 2010

Nowadays, geosynthetics for reinforcement and protection are widely applied to the waste landfill site. Current research indicates the potential for progressive failure in geosynthetic-soil system depends on the interface shear strength governed by several intrinsic factors such as moisture, normal stress, chemical, etc. In particular, the effect of the acidity and basicity from the leachate is intensively reviewed to assess the chemical reaction mechanism of interface shear strength under the cyclic loading condition. New multi-purpose interface apparatus(M-PIA) has been manufactured and the cyclic direct shear tests using submerged geosynthetics and soils under the different chemical conditions have been performed, consequently, the thickness of interface and shear stress degradation are verified. The basic schematic of the Disturbed State Concept(DSC) is employed to estimate the shear stress degradation in the interface, then, normalized disturbed function is obtained and analyzed to describe the shear stress degradation of geosynthetic-soil interface with chemical influence factors under dynamic condition.

• Proceedings of the Korean Geotechical Society Conference
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• 1992.10a
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• pp.131-136
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• 1992

발파공법은 비 점토성 지반의 심층 개량처리에 있어서 경제적이며 실용성 있는 방법이다. 발파에 의한 흙의 다짐효과는 복잡한 과정을 통하여 이루어지며 좋은 결과를 얻기 위해서는 발파 계획에 있어서 동 공법의 작용원리를 잘 이해하고 적용하여야 한다. 본 연구에서는 발파공법에 의한 흙의 다짐효과에 관한 과거의 연구자료를 광범위하게 조사하였다. 지반개량 작용원리에 관련하여 특별한 현상과 증거를 제시하는 실제 사례 자료를 기초로 하여 현재까지 흙의 밀도증가 요인을 설명해 온 개념은 발파에 수반되어 주변 주반에 발생하는 지반거동현상을 설명하기에 부족함이 있음을 지적하였다. 또한 발파지점 부근에 형성되는 액상화 영역과 그 외부 영역에서 각각 발생되는 과인간극수압 및 지반응력상태, 이에 따른 지반침하 형태 그리고 개량지반의 강성 및 강도특성에 관하여 고찰하였다.

• Water for future
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• v.29 no.2
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• pp.143-151
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• 1996

The dynamic responses in the subsurface outflow, surface saturation area, soil moisture storage are established by numerical experiments with Richards equation. In addition to this, the dynamical relationship between surface saturation area and subsurface outflow, and between surface saturation area and soil moisture storage are also determined by varying the hillslope shape, soil type, and boundary condition. The simulation results indicate that the dynamical relationships between surface saturation area and subsurface outflow, and between surface saturation area and soil moisture storage are approximated by the steadystate relationships. And the dynamic responses of subsurface outflow and surface saturation area are characterized by the double peaks although the rainfall pattern is asimple pulse input. As a result of numerical simulation, the physical mechanism for the occurrence of the double peaks is explained using the concept of variable source area.

• Journal of the Korean Geotechnical Society
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• v.28 no.3
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• pp.45-54
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• 2012

Various geosynthetics are widely applied to civil structures and waste landfill site for reinforcement and water resistance. The use of geosynthetics inevitably involves the coupled behaviors of different materials which include large displacement and strain-softening behaviors, etc. In this study, the effect of chemical element in the leachate on the interface shear strength under the cyclic loading condition was analyzed. The Multi-purpose Interface Apparatus (M-PIA) has been modified and cyclic direct shear tests have been performed. The submerging period of each specimen is 200 days. Additionally, the Field-Emission Scanning Electronic Microscopy (FIB) analysis has been also performed to induce the reason of the variation of disturbance function and verify the hypothesis on the decay-proof ability of geosynthetics. Consequently, the charateristics of chemical degradation of geosynthetic-soil interface are verified and the variation of the disturbance function is mainly caused by the different type of soil mineral decay, based on the FIB results.