• Journal of The Korean Association For Science Education
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• v.1 no.1
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• pp.45-52
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• 1978

In order to normalized the Earth Science Education, experiments and geologic field trainings are very important. But it have not carried out on account of many difficulties in current High School of Korea. These difficulties are lack of time, many problems of the text book, heavy teaching load, shortage of facilities and experimental equipments, and poor quality of teacher etc. The practical training of geologic field trip is very important in Earth Science Education. Finally, wirter propose a new teaching plan of geologic field training as follows: 1. The teacher must prepare the guide paper of field geologic training. 2. Subjects of practical training must simplify. 3. The teacher must take a pre-field investigation in order to get the teaching plan and the preparation of practical field training. 4. Let students observe for themselves on this guide, as if they were geologists. 5. The teacher must conclude about practical training after the working.

• Journal of the Korean Geotechnical Society
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• v.16 no.2
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• pp.23-30
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• 2000

The use of strut-preloading method is gradually increasing in braced excavations in Korea. And it is necessary to analyze the effects of strut preloading on the wall deflection, wall bending moment and strut axial force, etc. In this study, by using the analysis method of beams on elasto-plastic foundations, measured data and calculated results of 2 sites are compared and parametric studies of correlation between preloading and earth retaining structures in sandy soils are carried out in strut preloading application. As results, about 50%~75% of design strut load is effective as preloading force in considering the displacement and member forces of earth retaining structures. And the effective stiffiness of strut should be at least 25% of th ideal value in order to restrain the excessive increase of wall deflection and bending moments. As one of some methods to prevent excessive movements in braced excavation, to preload the strut is confirmed as more effective way than to increase the stiffiness of strut in braced wall, if the excessive axial force of strut due to preloading can be avoided.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.4
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• pp.517-526
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• 1997

This study is focused on the development and selection of the optimal cool tube system to maximize its thermal performance. Cool tube is devised to reduce the heating and cooling load of building by preheating or refreshing of intake air with buried pipes. Finite volume method is adopted to solve the conduction problem between the cool tube and earth. We examine the cool tube system for two operating periods, a short term(12 hours) and a long term(3 months). The results of short term operations reveal that condensation significantly influences and raises the exit air temperature. For long term operations, optimum conditions of cool tube system are obtained with variations of flow-rate, depth, length and diameter of cool tube.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.385-390
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• 2003

As growing of industrialization and increasing of population, the quantities of waste glasses are rapidly growing in the earth. It cause some problems such as the waste of natural resources and environmental pollution. In this context, recycling waste glass as a material of concrete has a great advantage environmentally and economically. This study is aimed to investigate the effect of load and deflection on fiber reinforced concrete slab model utilizing waste glass by fine aggregates. The flexural strength of the concrete including waste glass increased considerably, as the inclusion rate of steel fiber were increased. And the first crack load, maximum load and energy absorption capacity increased remarkably as the inclusion rate of steel fiber were increased. Therefore, in this study we confirmed the possibility of application for the usage of waste glass to the steel fiber reinforced concrete.

• Journal of the Korean Solar Energy Society
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• v.28 no.1
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• pp.19-24
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• 2008

The energy crisis is culminating for the life of the fossil fuel in the future which is come to end at $30{\sim}40$ years. Moreover above 90% of the energy in our country depend on importing and the crisis is more seγious than it of other countries. So architects devote low energy house research and it means underground space research have become public opinion. But there is not an accurate and utility method calculating the heating load of underground space. In this study it is proposed that the heating load is calculated by setting adiabatic thichness of soil and predicting underground temperature. The prediction of the underground temperature is calculated by the latitude, the level, the distance from sea, the condition of earth surface.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.9
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• pp.49-55
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• 2010

Many electric poles in the softground have been collapsed due to external load. In this study, 10 types of tests were performed with variation of location, numbers and depths of anchor blocks as well as depth of poles to find stresses acting on concrete electric poles. The stresses of concrete poles are relaxed at 600~700[kg] of tensile load, and stresses are concentrated at top of pole, and spread to lower part of pole. In the concrete pole collapse test, tensile load at failure was approximately 1,400[kg], which is twice of design load. As passive zone in the soil increases, the stresses acting on concrete pole are concentrated at lower part of pole based on moment arm earth pressure distribution.

• Journal of the Korean Society for Railway
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• v.3 no.2
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• pp.84-91
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• 2000

The general concept of reinforced roadbed in the high-speed railway is to cope with the soft ground for the bearing capacity and settlement of foundation soil. The cyclic plate load tests were performed to determine the behavior of reinforced ground with multiple layers of geogrid underlying by soft soil. With the test results, the bearing capacity ratio, elastic rebound ratio, subgrade modulus and the strain of geogrids under loading were investigated. Based on these plate load tests, laboratory model tests under cyclic loading were conducted to estimate the effect of geogrid reinforcement in particular for the high-speed rail roadbed. The permanent settlement and the behavior of earth pressure in reinforced roadbed subjected to a combination of static and dynamic loading are presented.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.9
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• pp.620-627
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• 2010

This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space. The fresh air is introduced into the double slab space and passes through the opening bored into the footing beam. The air is cooled by the heat exchange with the inside surface of the double slab space in summer, and heated in winter. This system not only reduces sensible heat load of the fresh air by heat exchange with earth but also reduces latent heat load of the fresh air by ad/de-sorption of underground double slab concrete. In this paper, we investigated the correlation between outdoor air temperature and outlet air temperature in the system. In conclusion, from the results of the high correlation we proposed a equation of regression for the outlet air temperature in the system by using linear regression analysis.

• Journal of the Korean Society of Industry Convergence
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• v.13 no.3
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• pp.169-181
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• 2010

This paper presents a feasibility study of a fresh air load reduction system by using an underground double floor space. The fresh air is introduced into the double slab space and passes through the opening bored into the footing beam. The air is cooled by the heat exchange with the inside surface of the double slab space in summer, and heated in winter. This system not only reduces sensible heat load of the fresh air by heat exchange with earth but also reduces latent heat load of the fresh air by ad/de-sorption of underground double slab concrete. In this paper, we proposed a simplified presumption method for the prediction of cooling and heating performance in the system. In conclusion the proposed method has been verified by comparing with the calculated value of the numerical analysis model by using nonlinear two-dimension hygroscopic question.

• Journal of the Korean GEO-environmental Society
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• v.10 no.6
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• pp.117-123
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• 2009

The mechanical behavior of a micropile due to horizontal load has not yet clearly identified in Korea. It has generally estimated from that of a traditional pile because there is no standard method even though it has shorter length. To tell the truth, its behavior is very different from a traditional pile's. Specifically, it is general fact that horizontal resistance of earth is one of the main factors to control the mechanical behavior of micropile. To this reason, a laboratory model has been made in this study to estimate the behavior of a micropile which loaded increasingly horizontally. The laboratory model has been designed to estimate both the behavior of load to displacement and skin friction to displacement. And the analysis of the latter was compared with the solution of strain wedge model. In the end, it was proved that the mechanical behavior of a micropile should be estimated from considering the horizontal resistance of earth.