• Journal of the Korean GEO-environmental Society
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• v.8 no.6
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• pp.5-12
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• 2007

Mudstone has characteristics that it has high enough strength and stiffness in a dry condition, but the strength and stiffness decrease in a wet condition with groundwater infiltration. The sliding of cut slope frequently encountered in Pohang area has been reported due to the rapid reduction of shear strength in mudstone after being exposed to the air. The study in this paper shows that mudstone having enough strength in a boring stage has lost the strength after installing PRD (percussion rotary drill) steel pipe pile inducing an insufficient bearing capacity. Field test has been performed to investigate the most favorable method for increasing a pile bearing capacity in mudstone with various methods such as MSG (Micro Silica Grouting) around the tip and side of a pile, the perimeter grouting combined with Micro pile reinforcement, and concrete filling after tip reinforcing grouting. MSG has been turned out to be the most favorable method for increasing a pile bearing capacity in mudstone, confirmed by the static load test.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.11c
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• pp.11-20
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• 1999

The method which makes the soft ground reinforced by using the geogrid, a kind of geosynthetics has been getting popular and its usefulness also has been increased due to reduction in costs, ease of construction and great exterior view, But the study on the frictional characteristics, which is the important factor in design, between reinforcement and soil is insufficient. In this study, compaction degrees were considered through large-scale pullout tests. As a part of studying on estimation of pullout frictional characteristics between soil and geosynthetics, pullout tests were peformed and from the result of pullout tests, pullout frictional parameters between soil and geosynthetics were obtained and pullout behaviors were learned.

• Korean Security Journal
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• no.1
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• pp.135-173
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• 1997

We study on the power of local autonomous fire fighting in Korea. Chapter I which sets out purpose, scope and method, is followed by Chapter Ⅱ , dealing largely with the organization, man-power, equipment, activites of local fire fighting administration and the fire fighting environment. Chapter III made a comparative study on the power of autonomous fire fighting, local budget , fire fighting activities, fire present conditions. It is followed by concluding abservation made in Chapter Ⅳ and Chapter V. We indicated a few disputed points on the power of local autonomous fire fighting and suggested several alternatives to improve our fire fighting administration system. The alternatives suggested are as followes : (1) Reinforcement of the man-power, (2) Regulation of the standard fire fighting power, (3) Improvement of the using on fire fighting facilities tax and state finance, (4) Aplication of the local borrowings, (5) Tax reduction and exemption on the fire fighting equip-ment investment, and so forth.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.56-63
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• 2023

This paper presents a method using finite element analysis and topology optimization to address the issue of overdesign in pressure-explosion proof enclosure doors for semiconductor manufacturing processes. The design conducted in this paper focuses on the pattern design of the enclosure door and its fixation components. The process consists of a solid-filled model, a topology optimization model, and a post-processing model. By applying environmental conditions to each model and comparing the maximum displacement, maximum equivalent stress, and weight values, it was confirmed that a reduction of about 13% in weight is achievable.

• Journal of Korean Association for Spatial Structures
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• v.24 no.2
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• pp.65-73
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• 2024

In this study, we propose an optimal design method by applying the Prefabricated Buckling Restrained Brace (PF-BRB) to structures with asymmetrically rigidity plan. As a result of the PF-BRB optimal design of a structure with an asymmetrically rigidity plan, it can be seen that the reduction effect of dynamic response is greater in the case of arrangement considering the asymmetric distribution of stiffness (Asym) than in the case of arrangement in the form of a symmetric distribution (Sym), especially It was confirmed that at an eccentricity rate of 20%, the total amount of reinforced PF-BRBs was also small. As a result of analyzing the dynamic response characteristics according to the change in eccentricity of the asymmetrically rigidity plan, the distribution of the reinforced PF-BRB showed that the larger the eccentricity, the greater the amount of damper distribution around the eccentric position. Additionally, when comparing the analysis models with an eccentricity rate of 20% and an eccentricity rate of 12%, the response reduction ratio of the 20% eccentricity rate was found to be large.

• Journal of the Korean Geotechnical Society
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• v.25 no.4
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• pp.19-29
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• 2009

In this study, a numerical analysis was performed to predict the sequential behavior of anchored retaining wall where the failure accident took place, and verified accuracy of prediction through the comparisons between prediction and field measurement. The emphasis was given to the wall behaviors and the variation of sliding surface based on the two different methods of elasto-plastic and finite element (shear strength reduction technique). Through the comparison study, it is shown that the bending moment and the soil pressure at construction stages produce quite similar results in both the elasto-plastic and finite element method. However, predicted wall deflections using elasto-plastic method show underestimate results compared with measured deflections. This demonstrates that the elasto-plastic method does not clearly consider the influence of soil-wall-reinforcement interaction, so that the tension force (anchor force and earth pressure) on the wall is overestimated. Based on the results obtained, it is found that finite element method using shear strength reduction method can be effectively used to perform the back calculation analysis in the anchored retaining wall, whereas elasto-plastic method can be applicable to the preliminary design of retaining wall with suitable safety factor.

• Wind and Structures
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• v.26 no.1
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• pp.45-56
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• 2018

Wind damage of urban trees arises to be a serious issue especially in the typhoon-prone areas. As a family of tree species widely-planted in Southeast China, the structural behaviors of Plane tree is investigated. In order to accommodate the complexities of tree morphology, a fractal theory based finite element modeling method is proposed. On-site measurement of Plane trees is performed for physical definition of structural parameters. It is revealed that modal frequencies of Plane trees distribute in a manner of grouped dense-frequencies; bending is the main mode of structural failure. In conjunction with the probability density evolution method, the fragility assessment of urban trees subjected to wind excitations is then proceeded. Numerical results indicate that small-size segments such as secondary branches feature a relatively higher failure risk in a low wind level, and a relatively lower failure risk in a high wind level owing to windward shrinks. Besides, the trunk of Plane tree is the segment most likely to be damaged than other segments in case of high winds. The failure position tends to occur at the connection between trunk and primary branches, where the logical protections and reinforcement measures can be implemented for mitigating the wind damage.

• Journal of Ocean Engineering and Technology
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• v.21 no.6
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• pp.81-86
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• 2007

In order to eliminate the hydration heat of mass concrete, this paper reports the results of hydration heat control in mass concrete using the OCHP (Oscillating capillary tube heat pipe). In the summarized results of the mock up experiments, distributing the heat pipe at 300 mm intervals based on the center of the test specimen was the most effective. A 200 mm turn interval for the heat pipe was measured to be the most appropriate, taking into account the reinforcement placing at the actual site. Therefore, when the hydration heat control method using the heat pipe developed in this study is applied, not only canconstruction efficiency & a reduction in the necessary construction time be expected, but so can outstanding economical effects.

• Journal of Haehwa Medicine
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• v.18 no.2
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• pp.131-140
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• 2009

The aim of this study is to find out benefits of symptom questionnaire for oriental medical treatments. We analyzed symptom questionnaire of Korean association of abdomen diagnosis and treatment. Conclusions are as below. 1. Appetite, taste and digestion have a deep connection with accumulation and muscular contracture, with which the method of reinforcement and reduction is decided. 2. Feces, urine and, sweat have a deep connection with accumulation and water, with which the method of diaphoresis, emesis and purgation is decided. 3. Thirst and chillness and fever have a deep connection with water poisons and feverish feeling, based on which the cold and heat is classified. 4. we can find out the lesions with departmentalized physical sections of the head and the face, the chest, the abdomen, the articulations, the limbs and the skin. 5. It is possible to select appropriate prescription and assess before & after treatment through the questionnaire.

• Korean Journal of Acupuncture
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• v.25 no.1
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• pp.1-18
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• 2008

Objectives : The aim of this study is to investigate the properties of Meridian Gi in $\ulcorner$Huangdineijing(黃帝內經)$\lrcorner$, specially one of the movement properties like that comings and goings of Gi. Methods : Through searching concepts and properties of Meridian Gi in several chapters of $\ulcorner$Huangdineijing(黃帝內經)$\lrcorner$, many phrases concerned with that properties could be explained and reconstructed into new motional shape of Meridian Gi. Results : The basic characters of comings and goings of Meridian Gi or genuine Gi originate from food essence, and that are like a kind of waves. The most important moments of acupuncture treatment is such time of it's short passing the acupoints, carrying out tonifying and purging methods by controlling the spirit. Conclusions : The Meridian Gi consists of anti-pathogenic Gi so called genuine Gi and pathogenic Gi. Medical doctor must correctly knows the flow of Meridian Gi to operate tonifying and purging method of acupuncture treatments in order to get the desired results. Also maintaining very sensitive state in diagnostic process, the most important key points is to control the spirit and adjust mental activities of both doctors and patients. The motional properties of Meridian Gi are actually concerned with the arrival of Gi and reinforcement-reduction along and against Meridian Gi.