• Journal of Satellite, Information and Communications
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• v.10 no.4
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• pp.52-57
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• 2015

For the purpose of drawing out the technological criteria for the development of the National Environmental Satellite Center Earth Station, some constructional conditions for the establishment of the National Environmental Satellite Center and several characteristics of National Environmental Satellite Center Earth Station to be developed in the near future were analyzed. In addition, the structure of Environmental Satellite Earth Station and its internal interfaces by analyzing the characteristics of National Environmental Satellite Center Earth Station were depicted. In this paper, some top level requirements of the Environmental Satellite Earth Station and several interface requirements between the Environmental Satellite Earth Station and the Satellite Control Center were systematically described.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.138-140
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• 2001

The Earth, along with its major components - land, atmosphere, and oceans, is at the core of the global environmental system. Changes in any component of the Earth thus strongly affect the global and regional environment. With the advent of the new century, many important decisions on agricultural, industrial, societal and political problems will depend upon the Earth's environment. Monitoring the Earth is thus important to capture any sign from the Earth which might be related to the environmental change. (omitted)

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.1496-1503
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• 2005

The study on the lateral earth pressure is briskly preformed for various conditions such as type of retaining walls, ground condition, and type of supporting systems. It is not simple to determine the distribution of lateral earth pressure accurately, however, because the lateral earth pressure is affected by various factors. This study is performed to analyze the behavior of earth retaining walls for new excavation contacting with existing excavation by comparing with the site measuring values before and after new excavation. On the base of observation, the distribution of strut axial forces is similar to that of ganeral earth retaining walls, but strut axial forces is increased by removal of existing earth anchors. When new excavation is performed contacting with existing excavation, the axial force of strut is decreased because of soil exclusion in the behind walls, but that force is increased after new exeavation. The analysis result show that the installation of strut in middle part makes a effect to not only 1 adjacent strut, but 3-5 adjacent struts. Also during new excavation strut axial forces is decreased by relaxation of total earth retaining wall system.

• 한국지구과학회:학술대회논문집
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• 2004.02a
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• pp.13-13
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• 2004

• 한국지구과학회:학술대회논문집
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• 2001.09a
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• pp.66-66
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• 2001

• Journal of the Korean Society of Earth Science Education
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• v.7 no.2
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• pp.266-275
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• 2014

The purpose of this study was to examine the effect of Earth System Education using multimedia on the elementary school students' environmental sensitivity and pro-environmental behavior. To verify this research problem, the subject of this study was fifth-grade students selected from two classes of M elementary school located in Busan city. For three months, the experimental group of 25 students was taught using multimedia. The comparison group also of 26 students was taught in normal classes which used a text-book. All students were given pre and post test to verify the effects of Earth System Education using multimedia on elementary school student's environmental sensitivity and pro-environmental behavior. The results from this study are as the following. First, Earth System Education using multimedia were effective on elementary school student's environmental sensitivity. Second, Earth System Education using multimedia were effective on elementary school student's pro-environmental behavior. Third, All most all experimental students were satisfied with Earth System Education using multimedia. In conclusion, Earth System Education using multimedia showed very positive effects on improvement of elementary school students' environmental sensitivity and pro-environmental behavior.

• Journal of The Korean Society of Agricultural Engineers
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• v.47 no.4
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• pp.53-61
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• 2005

A series of laboratory tests was carried out fur analyzing of seepage characteristics of two-layers embankment model which consists of gravel and earth fill layers. Gravel layers were built under the earth fill for a half and one-third width of earth fill of the model. Permeability of earth fill was ranged between $5.00\times10^{-5}\~3.00\times10^{-4}\;m/s$.. The tests were performed with hydraulic gradients(i), $0.10\~0.55$. From the test results, hydraulic head of earth fill with gravel layer was 1.6 times higher than that of earth fill without gravel layer. Seepage rate was increased up to $4\~22$ times and safety factor for piping was decreased to $13\~43\;\%$ comparing the earth fill with gravel layer to that without gravel layer. The gravel layer under the earth fill could, in general, give some serious seepage problems to seadike embankment.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.457-464
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• 1999

The active earth pressure on the retaining wall is reduced by 3-Dimensional effects of the ground. Therefore, the test was focused on reducing the earth pressure on the retaining wall by inserting the vertical reinforcement in the backfill ground to develope the 3-Dimensional effects. Model tests in sand were peformed to measure the 3-Dimensional effects of the vertical reinforcement on the active earth pressure and its distribution and results were compared with the theories. The size of the vertical reinforcement, the geometry of the backfill space, and the wall friction of vertical reinforcement were varied. It was observed that the active earth pressure and its distribution on the underground structure were affected by the size of the vertical reforcements and wall friction.

• Geotechnical Engineering
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• v.9 no.1
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• pp.59-68
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• 1993

In deep excavations for creation of underground spaces, it would be difficult to predict earth pressure, especially multilayered ground including rock strata. The earth pressures and displacements on the retention walls are measured by load cell, strain gauge and inclinometer which were installed at struts or anchors at 4 deep excavation sites in Seoul area. In this paper, the measured earth pressure from the struts or anchors are compared with Peck's empirical values, and the coefficient of the earth pressures for each strata and horizontal wall displacement are investigated. The coefficient of earth pressure distribution, a(0.65zka), in the flexible and the rigid walls was about 74% and 88% of Peck's value respecitively. The measured earth pressure distributions for the 4 sites showed about 70%∼80% of Peck's empirical values and the average earth pressure coefficients based on the measured data were 0.3 for the felted layer, 0.23 for the weathered rock and 0.19 for the weak rock. The maximum w리1 displacements were found to be less 0.2% of excavation depth.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.489-496
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• 1999

The safety of a structure can be improved by applying the three dimensional passive earth pressure. Because the three dimensional passive earth pressure is much larger than the two dimensional passive earth pressure and it is determined by the size(width B and height H) and the wall frictional angle of the resistant wall. Therefore, the three dimensional passive resistance behavior was studied through the model tests in sandy ground, where the size of the resistant wall and the wall frictional angle were varied. The results show that three dimensional passive earth pressure is 1.1∼3.4 times larger than that of the two dimensional value depending on the wall size and the wall friction.