• Transactions of Materials Processing
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• v.12 no.2
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• pp.94-101
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• 2003

For the optimal net shape forging of S semi-solid materials (SSM), it is important to predict the deformation behavior and defects of materials. Among these defects, liquid segregation is detrimental to produce products with good mechanical properties. Moreover, to apply a numerical method to thixoforging, it is very important to prevent a liquid segregation during forming process. The liquid segregation phenomena in deformation behavior of semi-solid material with variation of test specimen size were studied. The SSM compression tests were performed by dynamic material test system with a furnace. Stress-strain curves and microstructures of SSM were investigated, and Porosities were analyzed to evaluate the effects of experiment parameters on liquid segregation.

• KCI Concrete Journal
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• v.13 no.2
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• pp.3-9
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• 2001

Pseudo dynamic test for seven circular RC bridge piers has been carried out to investigate their seismic performance subjected to expected artificial earthquake motions. The objective of this experimental study is to investigate the hysteretic behavior of reinforced concrete bridge piers, which have been widely used for railway and urban transportation facilities. Important test parameters are confinement steel ratio, and input ground motion. The seismic behavior of circular RC bridge piers under artificial ground motions has been evaluated through displacement ductility, cumulative energy input, and dissipation capacity. It can be concluded that RC bridge piers designed in a limited ductile behavior provision of Eurocode 8 have been determined to show good seismic performance even under moderate artificial earthquakes.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.4
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• pp.340-345
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• 2010

For the conversion into hydrogen society, not only studying facilities of hydrogen production, storage, transportation and charging system but also developing technique of ensuring safety are essentially needed. Hence, for the first step of that, evaluated the hydrogen embrittlement of Inconel alloy 617, Ni-based super heat-resisting alloy, by small punch test. Prepared the various specimens through changing electrochemical charging time and measured the toughness degradation of the specimens by small-punch test. The analysis of hydrogen embrittlement behavior were carried out by investigating the fractured surface of specimens. This study has significance on revealing mechanism of hydrogen embrittlement behavior and the factor affecting hydrogen embrittlement in the future study.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.475-480
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• 2002

Tension tests of six half-thickness concrete containment wall elements were conducted as part of a Korea Atomic Energy Research Institute (KARRI) program. The aim of the KAERI test program is providing a test-verified analytical method for estimating capacities of concrete reactor containment buildings under internal overpressurization from postulated degraded core accidents. The data from the tests reported herein should be useful for benchmarking method that requires modeling of material behavior including concrete cracking and reinforcement/concrete interaction exhibited by the test. Major test variable is the compressive strength of concrete and its effect on the behavior of prestressed concrete panel subjected to biaxial tension.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.107-108
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• 2013

In this study, combustibles investigation and fire growth rate experiment were performed for predicting initial fire behavior in buildings. Combustibles investigation was performed for residential buildings, which is most frequently affected by fire in Korea. Spatial characteristics and combustibles properties were separately investigated, and occupied area and layout characteristics of combustibles were identified to produce general layout models. Of the layout models, room was selected for fire test of a single compartment. From this test, fire propagation for each combustible was identified, which was delayed compared to the summed heat release rate of a single combustible.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.176-179
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• 2005

Spray casting of hypereutectic Al-Si based alloy has been reported to provide distinct advantages over ingot metallurgy (IM) or rapid solidification/powder metallurgy (RS/PM) process in terms of microstructure refinement. Hypereutectic Al-Si based alloys have been regarded attractive for automotive and aerospace application, due to high specific strength, good wear resistance, low coefficient of thermal expansion, high thermal stability, and good creep resistance. In this study, hypereutectic Al-25Si-2.0Cu-1.0Mg alloy was prepared by OSPREY spray casting process. High temperature deformation behavior of the hypereutectic Al-Si based alloy has been investigated by applying the internal variable theory proposed by Chang et al. The change of strain rate sensitivity and Creep transition were analyzed by using the load relaxation test and constant creep test.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.369-374
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• 2000

This study was conducted to investigate the seismic behavior assessment of circlular-tied bridge piers, particularly with regard to assessing the displacement ductility. The experimental variables of bridge piers test consisted of transverse steel details, amount and spacing different axial load levels etc. The test results indicated that reinforcement concrete bridge piers with confinement steel by the code specification exhibited sufficient ductile behavior and seismic performance. Aldo, it is found that current seismic design code specification of confinement steel requirements may be revised.

• Proceedings of the Korean Geotechical Society Conference
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• 2002.10a
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• pp.390-397
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• 2002

In this study, static pile load tests with load transfer measurement for a pile socketed into weathered rocks were performed. Axial load transfers during static pile load test were measured and analyzed. Three large diameter piles socketed into weathered rock were behavior behaved as friction pile.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.215-216
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• 2023

Leakage in the structure due to the irregular flow of groundwater in the underground structure penetrates into internal spaces such as underground parking lots and basement through underground walls, which is expensive in terms of maintenance of the building. In this study, various composite waterproofing methods installed on the outer walls of underground structures were selected to evaluate the structural performance of composite specimens due to bending behavior through experiments and analysis on bending test behavior on concrete attachment surfaces.

• Journal of the Korean Home Economics Association
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• v.28 no.1
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• pp.105-124
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• 1990

The purpose of this study is to investigate 1) the level of the city housewives' sense and behavior of wedding and ancestral service according to the background variables, 2) the relationship of the sense of wedding and ancestral service and behavior, and 3) what the most influential factors are. For the purpose of this study, 700 questionnaire were distributed to the housewives who live in Seoul and collected during the February 1989. And the measuring instruments are composed of 9 questions, 11 questions of the sense of wedding service, 12 questions of the sense of ancestral service, 11 questions of the behavior of wedding service, and 12 questions of the behavior of ancestral service. To obtain the sense and behavior of wedding and ancestral service scale, item analysis through Pearon's correlation and factor analysis, frequency distribution, percentile, mean, standard deviation, t-test, F-test, Pearson's γ, Paired-t-test, Duncan's Multiple Range Test, and Stepwise multiple Regression were used for data analysis. The major fidnigs are as follows: 1. The general tendency of the city housewives' sense of wedding service was modern. That of the city housewives' sense of ancestral service was the mid level of the traditional and the modern. According to background variable (ie: age, educational level, the number of children, the duration of marriage, religion, the existence of job, the existence of married son and daughter), the city housewives' sense of wedding service is different significantly. Accoring to background variable(ie: age, educational level, the average home income a month, the number of children, the duration of marriage, religion, the existence of married son and daughter), the city housewives' sense of ancestral service is different significantly. 2. The general tendency of the city housewives' behavior of wedding service was modern. That of the city housewives' behavior of ancestral service was somewhat modern. According to background variable(ie: age, educational level, the number of children, the duration of marriage, the existence of married son and daughter, the form of family), the city housewives' behavior of wedding service is different significantly. According to background variable(ie" age, educational level, the number of children, the duration of marriage, religion, the existence of job, the existence of married son and daughter), the city housewives' behavior of ancestral service is different significantly. 3. There were positive correlation between the city housewive' sense and behavior of wedding and ancestral service(P<.001). And the housewives' sense of wedding service was modernized than that of ancestral service, the housewives' behavior of ancestral service was modernized than that of wedding service. 4. The city housewives' sense of wedding service was the duration of marriage(β=-.226), influential factor. And influential factors on that of ancestral service were educational level(β=.250), the existence of married son and daughter(β=-.123), number of children(β=-.101). The influential factors on the city housewives' behavior of wedding service were age(β=-.193), the form of family(β=.097). And that of ancestral service were educational level(β=165), the number of children(β=-.157).