• Geomechanics and Engineering
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• v.10 no.5
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• pp.657-676
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• 2016

In this paper, the active lateral earth pressure is evaluated using the stress characteristics or slip line method. The lateral earth pressure is expressed as the lateral earth pressure coefficients due to the surcharge, the unit weight and cohesion of the backfill soil. Seismic horizontal and vertical pseudo-static coefficients are used to consider the seismic effects. The equilibrium equations along the characteristics lines are solved by the finite difference method. The slope of the ground surface, the wall angle and the adhesion and friction angle of the soil-wall interface are also considered in the analysis. A computer code is provided for the analysis. The code is capable of solving the characteristics network, determining active lateral earth pressure distribution and calculating active lateral earth pressure coefficients. Closed-form solutions are provided for the lateral earth pressure coefficients due to the surcharge and cohesion. The results of this study have a good agreement with other reported results. The effects of the geometry of the retaining wall, the soil and soil-wall interface parameters are evaluated. Non-dimensional graphs are presented for the active lateral earth pressure coefficients.

• Journal of the Korean Society of Earth Science Education
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• v.8 no.3
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• pp.297-308
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• 2015

The purpose of this study was to suggest the earth science lesson model based on the creativity character education. To conduct this study, the curriculum revision in 2009 was analyzed by the causal mapping method. One after another, the creativity character education and earth system education were analyzed by the same method. Through as mentioned above, the key words which have relating concepts each other were picked out. Lastly, the key words were connected and compounded for the earth science lesson model based on the creativity character education. The model indicates that the earth science lesson based on the creativity character education requires the reconstructs of the processing and contents of the lesson. In other words, the teaching/learning must be progressed as corresponding between scientific facts and mental recognition, scientific concepts and compounding thinking skill, scientific laws and reconstructing thinking skill. In contents were reconstructed as relating to knowledge, creativity, characters and guidance counseling. The results of this study suggested the earth science lesson model based on the creativity character education needs developing and applying teaching/learning materials and managing discussing and cooperative learning.

• Journal of the Korean earth science society
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• v.36 no.6
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• pp.580-590
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• 2015

The purpose of this study was to investigate the correlation among science gifted students' self-reported knowledge and self-perceived importance about Earth systems, and their science motivation. Ninety three seventh graders participated in this study who enrolled at Science Gifted Institute of K university. The correlation was measured by a validated Earth systems survey and Science Motivation Questionnaire (SMQ). The data were analyzed at the margin of error probability 0.05 using correlation and regression analysis. The result of reliability for items turned out high because the Cronbach's alphas were .896~.937. Results indicated that the correlation between self-reported knowledge on Earth systems and science motivation showed a correlation coefficient .656, whereas the correlation between importance on Earth systems and science motivation was .387, which was regarded as low. On the other hands, the result of regression analysis depicted that non-std. coefficients between students' self-reported knowledge about Earth systems and science motivation were .548 (.077), which lead to the conclusion that students' knowledge on Earth systems explained 43% of science motive-variation. It implied that Earth systems education program could impact the increased motivation of science gifted-students. Therefore, this study suggests that the various Earth systems education programs could be developed and implemented in order to increase students' motivation on studying science in general and Earth science in specific.

• Journal of the Korean Society of Safety
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• v.24 no.5
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• pp.57-62
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• 2009

In this study, the numerical analyses regarding the distance between the guardrail and the reinforced earth wall as parameter were performed to determine the safe distance of guardrail installed on reinforced earth wall from the reinforced earth wall. The analyses were fulfilled by increasing the distance between the guardrail and reinforced earth wall from 150mm to 750mm. The computer program used in this research is LS-DYNA, which is very' popular in analysis of vehicle collision. Ford single unit truck in NCAC was employed as the model of vehicle and the velocity of vehicle collision was 80km/hr. As a results of analyses, the safety of guardrail was secured regardless of the distance between the guardrail and block of reinforced earth wall. However, to secure the safety of block of reinforced earth wall the distance between the guardrail and block of reinforced earth wall should be over 600mm.

• 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.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.71
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• pp.297-324
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• 2016

China not only has the largest amount of rare earth reserves, but it also produces the most rare earth products. However, China lacks appropriate supervision and management systems of its rare earth industry. The Chinese government's inappropriate mechanisms have been cause for reckless development by national rare earth providers characterized by excessive competition, environmental pollution, and smuggling. In response to the problems, China implemented regulatory measures to restructure the rare earth industry. The Chinese central government intensifies its efforts to control the total quantity of rare earth products and tackle environmental pollution. Six leading conglomerates have been selected to promote the Chinese central government's policy. A new environmental guideline has been drawn up to reduce the discharging of wastewater and air pollution substance. Huge transition and a great influence of its policy changes are expected. These policy changes are bound to entail huge transitions, and the policy is expected to have a great influence in the future structure of the rare earth industry. In consideration of these changes, the Korean government, in collaboration with private enterprises needs to take appropriate measures, such as overseas resources development, R&D expansion, tactical stockpiling, professional manpower training and so on.

• The KIPS Transactions:PartD
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• v.18D no.5
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• pp.323-328
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• 2011

For content-based image retrieval, the earth mover's distance and the optimal color composition distance are proposed to measure the dissimilarity. Although providing good retrieval results, both methods are too time-consuming to be used in a large image database. To solve the problem, we propose a new distance function that calculates an approximate earth mover's distance in linear time. To calculate the dissimilarity in linear time, the proposed approach employs the space-filling curve. We have performed extensive experiments to show the effectiveness and efficiency of the proposed approach. The results reveal that our approach achieves almost the same results with the EMD in linear time.

• Journal of the Korean Solar Energy Society
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• v.24 no.2
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• pp.63-71
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• 2004

Energy and environmental concerns accelerate the interest in passive solar heating in buildings, which utilizes solar energy through natural heat transfer. Moreover concerns about environmentally friendly materials were also increased. This study aims to evaluate the thermal performance of a Trombe wall built with earth. The thermal performance of the Trombe walls was analysed with results from computer simulations with TRNSYS 15. The thermal performance of the three types of Trombe wall was compared.: concrete. rammed earth. adobe. It was found that Trombe wall with the thermal storage wall of earth performed better than that of concrete. Rammed earth and adobe Trombe walls gained 4.7% and 12.8% more solar energy. respectively. than the concrete Trombe wall. In earth-applied Trombe walls. the energy gain by natural convection released from the airspace was about 75% of the total solar gains. that took 15% more than concrete Trombe wall. Rammed earth and adobe Trombe walls seem to be more suitable for buildings that use mostly in daytime. such as school, office and so on.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.19 no.6
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• pp.22-28
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• 2005

The electrical characterstic of earth is the most dominant factor for grounding design and an earth is typically represented by a uniform medium with the specific earth resistivity, which is unique for a specific site. For a hand-working grounding design using a specific earth resistivity requires a process converting a real earth of complex medium into a simple uniform medium In this paper, we suggest a procedure to convert a multi-layered earth s into a simpler uniform earth for grounding design of Myanmar 500[kV] transmission towers.

• Journal of the Korean Society of Earth Science Education
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• v.5 no.1
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• pp.88-94
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• 2012

This study was created to resolve the problems embedded in the formal measuring experiments to determine the earth's size in the current curriculum, to develop an updated measuring experiment to determine the earth's size and to establish its effect. For this study, pre-service elementary teachers, who had attempted the experiment of measuring the size of the earth when they were in middle school, performed the experiments in the existing national curriculum, and their responses, collected through in-depth interviews, were examined. To begin with, the pre-service elementary teachers conducted the experiment of measuring the earth size and they recorded the problems while performing it. At the end, an in-depth interview was administered. Based on the problems, an updated measuring experiment to determine the earth's size was suggested to be applied to the same contents and be analyzed through the in-depth interviews. Common themes which were mutually categorized and analyzed by the two researchers were obtained based on the records produced while conducting the experiment and the in-depth interview data. The teachers mentioned that the experiments for measuring the size of the earth in the current curriculum gave rise to difficulties in measuring precisely the angles between the string and the post. Also, there has been a scientific contradiction that solar altitudes were increased in a high latitude region, instead of decreased. For this reason, an alternative method has been developed to measure the earth's size using the distance and the solar altitude difference of two places. The teachers all agreed that by using the updated measuring experiment, they can acquire more precise measurements and it is easier, faster and consequently more effective than the existing methods. Through the results of this study, I suggest that the newly developed experiment by the researchers can overhaul the problems of the current experiments and it can be an effective alternative to the current experiment.