• Journal of the Korean earth science society
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• v.34 no.2
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• pp.136-147
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• 2013

This study examined the effect of the Antarctic Oscillation (AAO) in June on the June rainfall in Korea by using a correlational statistical analysis. Results showed that there is a highly positive correlation between the two variables. In other words, the June rainfall in Korea is influenced by the Mascarene High and Australian High that are strengthened in the Southern Hemisphere, which is a typical positive AAO pattern. When these two anomalous pressure systems strengthen, the cold cross-equatorial flows in the direction from the region around Australia to the equator are intensified, which in turn, force a western North Pacific subtropical high (WNPSH) to develop northward. This pressure development eventually drives the rain belt to head north. As a result, the Changma begins early in the positive AAO phase and the June rainfall increases in Korea. In addition, a WNPSH that develops more northward increases the landfall (or affecting) frequency of tropical cyclones in Korea, which plays an important role in increasing the June rainfall.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.5
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• pp.505-511
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• 2016

The aim of this study is to investigate the thermoforming characteristics of an inner case with three refrigerator cavities using three-dimensional(3D) thermoforming analyses. We perform fundamental formability analyses using a 3D model of the mould for the inner case. We carry out tensile tests at the elevated temperature to examine the properties and characteristics of the thermoformed material. Then, we design sub-processes of the thermoforming process for the inner case. In addition, we develop suitable finite-element models for different sub-processes. We investigate the deformed shapes and thickness distributions of the inner case for different sub-processes using the results of the thermoforming analysis. Finally, we discuss the formability and thermoforming characteristics of the inner case with three cavities.

• Journal of Gifted/Talented Education
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• v.13 no.3
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• pp.69-85
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• 2003

This study verified the differences of thinking styles between science highschool students and general students in reference to academic achievement. The subjects of this study are 211 high school students, who were composed of 122 science school students and 93 general school students. The significant results of this study are as follows: First, science highschool students showed more distinguishable differences in thinking style than general highschool students. Second, the former rather than the latter is revealed to be more variable in thinking styles explaining academic achievement. Next, in case of science highschool students, thinking style which is affected by intelligence is turned out to be an indirect factor influencing academic achievement. Finally, I verified the importance of distinction of science highschool students and the usefulness of thinking styles, gave suggestions on the reformation and direction of current school education of science-gifted students.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.2
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• pp.135-142
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• 2009

This study investigates the characteristic properties of strength, flowability, durability and drying shrinkage to control strength and to reduce heat of hydration of high performance concrete using crushed stone fines. According to the experimental results, when crushed stone fines are increased every 10%, $10{\sim}15%$ of compressive strength is decreased and flowability of high performance concrete is effectively improved due to the decrease of modulus of deformation and confined water ratio. When crushed stone fines are replaced every 10%, $4^{\circ}C$ of the highest adiabatic temperature rise is decreased by reducing the unit cement. However, 5% of drying shrinkage is increased in the same condition In the meantime, durability of high performance concrete is excellent, having over 100% of good relative dynamic modulus of elasticity due to fineness of formation mused by the increase of the unit powder content and the improvement of flowability, without regard to the replacement of crushed stone fines. Therefore, It can be said that the usage of crushed stone fines can control the strength of high performance concrete by replacement and reduce heat of hydration.

• Korean Journal of Environment and Ecology
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• v.14 no.4
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• pp.303-310
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• 2001

계룡산국립공원 연애골 계곡부(해발 170-630m)의 해발고와 사면부위에 따른 교목층과 아교목층의 산림구조를 조사하기 위하여 해발고와 사면부위에 따란 48개 조사구를 설정하였다. 계곡 정부를 제외할 때, 해발고가 높아짐에 따라 교목층의 밀도는 증가하는 반면 아교목층의 밀도는 감소하였으며, 교목층과 아교목층 전체의 밀도는 별차이가 없었다. 흉고단면적은 계곡 하부와 중부가 상부에 비하여 높았다. 해발고가 높아짐에 따라 중요치가 증가하는 경향을 보이는 수종은 산길나무, 팥배나무, 쇠물푸레 등이었으며, 감소하는 경향을 보이는 수종은 산벚나무, 졸참나무, 때죽나무, 갈참나무, 밤나무 등이었다. 사면 하부에서 갈수록 중요치가 증가하는 경향을 보이는 수종은 소나무, 신갈나무, 쪽동백나무, 쇠물푸레 드잉었으며, 감소하는 경향을 보이는 수종은 느티나무, 때죽나무, 비목나무, 고로쇠나무 등이었다. 해발고대별 종다양의 범위는 0.971~1.273이었으며, 종다양도와 종수는 계곡 중부가 계곡하부와 상부에 비하여 다소 낮았으나 균재도는 유사하였다. 계곡 정부를 제외한 해발고대간 유사도지수는 30.8~63.7%, 사면부위간 유사도지수는 69.8~79.5%로서 사면부위보다 해발고에 따른 종구성상태의 변화가 더 크게 나타났다. 수종별 중요치에 의한 Cluster 분석 결과 계곡 하부의 사면 상. 중, 하부에 위치한 때죽나무-소나무-낙엽활엽수군집, 계곡 중부의 사면 상, 중, 하부에 위치한 굴참나무-낙엽활엽수군집 계곡 상부의 상. 중. 하부에 위치한 물푸레나무-낙엽활엽수군집, 계곡 정부에 위치한 소나무-신갈나무군집 등 4개 유형군집으로 구분되었다. 종상관을 분석한 결과 느티나무, 물푸레나무, 고로쇠나무, 팽나무, 회나무 등 5개 수종간, 소나무, 쇠물푸레, 산철쭉 등 3개 수종간 유의적인 정의 상관을 보였다. 유의적인 정의 상관을 보인 느티나무, 물푸레나무, 회나무, 사람주나무 등 4개 수종 모두 소나무와 유의적인 부위 상관을 보였으며, 유의적인 정의 상관을 보인 졸참나무는 유의적인 정의 상관을 보인 물푸레나무, 사람주나무, 회나무와, 유의적인 부의 상관을 보였다.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.153-159
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• 2000

Large-scale simulated lysimeter experiments were conducted for 4 years as a fundamental study to develop enhanced landfill stabilization method, which accelerate stabilization time and make efficient practical use of self-purification capacity of pollutants in semi-aerobic solid waste landfill. The amount of TOC(total organic carbon) decomposition increased as the landfill depth increased. In case of T-N(total nitrogen), the self-purification capacity increased linearly with the landfill thickness until it reached a maximum level of 6 m. Beyond this level, the self-purification capacity was not increased. The results from lysimeter experiments indicate that 6m of landfill thickness is optimum for self-purification capacity of pollutants considering the mass balance of TOC and T-N.

• Journal of Korea Water Resources Association
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• v.46 no.9
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• pp.957-967
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• 2013

High turbidity submersion due to torrential downpour is one of the factors that influences the plant growth. This study is focused on analyzing the plant's growth rate for Salix species such as gracilisyla, koreensis, glandulosa when these trees are waterlogged. The length of shoots for this control group in the natural state is 33.4% (gracilisyla), 24.3% (koreensis), 23.9% (glandulosa), however, they stopped growing in submersion. Compared to the leaf number of Salix species of this control group in the natural state, 144.5% (gracilisyla), 77.3% (koreensis), 40.3% (glandulosa) in the natural state 30 days, in 30 days submersion, the number of leaves is zero except koreensis. In the results of this experiment, Salix species stopped growing quickly when submersed. This study concludes that it is necessary to plant eco-friendly plants around the slope of the reservoir and dam where flooding takes place frequently.

• Journal of the Korea Concrete Institute
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• v.18 no.4 s.94
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• pp.559-568
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• 2006

The purpose of this study is to evaluate the mechanical performance and fire resistance of wet-mixed high strength sprayed polymer-modified mortar in order to protect tunnel lining system which are in the event of fire disaster. Since the current commercial fire-resistant materials reproduce the low strength issue of mortar, this study aims to provide an enhanced fire-resistant mortar with a proper strength. Normally, a large temperature gradient phenomenon arise in the vicinity of free surfaces which are fully exposed in the event of persistent flame. Thereby, the determination of optimal cover depth of wet-mixed high strength sprayed polymer-mortar(WHSPM) is important for fire-resistance of tunnel lining system. With comparison of current commercial fire-resistance materials and WHSPM, the experimental result of WHSPM shows the better fire-resistant performance than the others. In addition, the cover limitation should be controlled by minimum 4cm depth in order to avoid fire-induced damage.

• Archives of design research
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• v.14 no.2
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• pp.245-252
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• 2001

On the assumption that the layout of refrigerator for domestic market does not match with the eating habits of the Korean, this study suggests a way of improvement for usability of the refrigerator by re-arranging layout of inner shelves through behavioral analysis with the video ethnography. On the result of analysis, it can be found that the layout of inner shelves of the most refrigerators differs from the habits of cooking and preparing meals of Korean food, so the author propose a new layout to exchange the usage of the 3rd shelf with the vegetable box of the bottom level. It can be effective method to improve the usability by assigning appropriate usage for each shelf. To extract internal design factors of product, which is related to the specific living habits such as a refrigerator, understanding of user behavior must be accomplished at the first stage. The author found that the analysis of user behavior using the video ethnography is useful for this purpose, because it can be used to explore unpredictable design factors from user's real life.

• Journal of the Korean Vacuum Society
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• v.12 no.2
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• pp.136-143
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• 2003

In this paper, high purity RF sputter-type ion source for non-mass separated ion beam deposition was evaluated. The fundamental characteristics of the ion source which is composed of an RF Cu coil and a high purity Cu target (99.9999 %) was studied, and the practical application of Cu thin films for ULSI metallization was discussed. The relationship between the DC target current and the DC target voltage at various RF power and Ar gas pressures was measured, and then preparation conditions for Cu thin films was described. As a result, it was found that the deposition conditions of the target voltage, the target current and the Ar pressure were optimized at -300 V, 240 W and 9 Pa, respectively. The resistivity of Cu films deposited at a bias voltage of -50 V showed a minimum value of 1.8 $\pm$ 0.1 $mu\Omega$cm, which is close to that of Cu bulk (1.67 $mu\Omega$cm).