• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.6
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• pp.48-57
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• 2020

This study was aimed to determine the history of Son keechung laurel tree, which is designated and managed as Seoul Metropolitan Government Monument No. 5. Sohn keechung's victory in the marathon at the 1936 Berlin Olympics served as an opportunity to encourage great pride and national spirit for the Korean people's national spirit who had spent their painful days under Japanese colonial rule. The seedlings that Son keechung received at the time are currently growing at Son Keechung Sports Park on the hill in Manri-dong, west of Seoul Station, and are Quercus palustris. That variety of Tree is native to the United States. The 11th Berlin Olympics, held in 1936, is a golden opportunity for Hitler to show off the history and cultural excellence of the German race, so it does not make sense to award victors an American giant oak instead of the German oak tree. The Seoul Metropolitan Government and various media outlets made a fait accompli due to Hitler's simple mistake. However, this study revealed that the laurel that Son received was the Quercus robur, based on the articles of the Korean newspaper, the German daily newspaper, and the recently introduced article of Der Spiegel, a leading German weekly magazine. Based on these circumstances, I would like to suggest that the originally awarded Quercus robur be planted in Son keechung Memorial Park and that the newly discovered history be notified on the Seoul Metropolitan Government website and various records.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.3
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• pp.130-140
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• 2018

An AU-composite beam based on U-shaped steel beams and steel plate anchors of type A was developed. The composite beam reduced the height of the building floor and construction cost. In addition, it decreased the length of construction work, and improved the flexural strength and stiffness as a form of tubes. In this study, AU-composite beams were tested directly and their performance was evaluated through bending experiments. The strength of the specimens was increased initially by linear loads and reached a maximum strength due to destruction of the concrete slab. All of the experiments showed more than 85% of the maximum stress and performed gentle movement. In addition, there was good composite behavior with the steel plate anchor that had excellent composite effects and reached full strength until the maximum strength was reached. When the thickness of the steel plate was increase, the flexural stiffness and strength of the specimen were improved. Therefore, the flexural strength of AU-composite beams can be estimated using the flexural strength formula according to the KBC 2016.

• Journal of Korean Society of Steel Construction
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• v.29 no.6
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• pp.423-434
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• 2017

In this paper a systematic numerical analysis is performed to obtain the hysteresis behavior of partially restrained top and seat angle connections subjected to cyclic loading. This connection includes superelastic shape memory alloy (SMA) angles and rods in order to secure the recentering capacities as well as proper energy dissipation effects of a CFT composite frame. The three-dimensional nonlinear finite element models are constructed to investigate the rotational stiffness, bending moment capacity and failure modes. A wide scope of additional structural behaviors explain the different influences of the connection's parameters, such as the various thickness of connection angles and the gage distance of steel and SMA rods.

• Fire Science and Engineering
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• v.30 no.5
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• pp.82-86
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• 2016

The fire resistance of a statistically indeterminate beam made of fire resistant steel was analyzed using the mechanical and thermal databases and compared with that of an indeterminate beam constructed of ordinary structural steel to not only determine the fire resistance performance of a statistically indeterminate beam itself, but also to determine if it is stable to test the fire resistance performance with a determinate beam built with ordinary structural steel instead of an indeterminate beam made from fire resistant steels. The results showed that the fire resistance of an indeterminate beam consisting of fire resistant steels is better than that of a determinate beam made of SS 400 and if the length of the beam built with FR 490 is longer, the displacement of the beam is higher. In addition, the fire test with a determinate beam made of SS 400 is was more conservative than that of an indeterminate beam made of FR 490 in the range of the same length. Therefore, another measure should be considered if beams built with FR 490 are longer than thos of SS 400.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.8
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• pp.3729-3744
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• 2011

As the size of structures become larger by civil and architectural structures becoming large, deeply underground, and high-rise, the conditions of underground foundation vary according to the location that the lack of bearing capacity locally because of ununiform of foundation in some parts is frequent. Generally, when the foundation is not homogeneous, the acquisition of safety through applying the most conservative foundation method possible becomes the focus to secure the stability of the superstructures. It is considered as because of inability to verify the application and stability and application of construction of different foundations through an outlined review because of lack of study in case of different foundation of mixed use of direct foundation and pile foundation. Therefore, through measurement interpretation of the different foundation in which the direct foundation and pile foundation are mixed in use, the grounds in which the hypothetical bearing capacity changes dramatically was modeled to evaluate the applicability of different foundations. Also, based on the results of measurement interpretation, various foundations are created by using plaster, Joomunjin standard soil, and rubble to conduct an indoor model test to compare and analyze the movement of pile foundation and different foundations. Based on such research results, the stability and applicability of the different foundations which is more efficient and economical than the existing foundations in case of grounds in which the bearing capacity changes dramatically by comparing and analyzing the different foundations (direct foundation + pile foundation) with the conservative pile foundation and mat foundation. As a result, when the different foundation is applied, the overall settlement amount increased than the conservative pile foundation. However, the difference was very minute and it has been confirmed to be no issue as a result of assessment of stability of the differential settlement of structures through critical angle displacement.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.11
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• pp.556-562
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• 2001

Spacer is used between main tank and auxiliary tank for on load tap changer in gas insulated power transformer. This paper deals with electrical design of spacer and discusses different analysis method of between 2D FEM(finite element method) and 3D FEM. To design spacer, we modeled structure of two kind of coaxial cylinders of spacer conductors and analysised electric field of spacer at impulse and induced test voltage condition. Spacer has 13 conductors and electric field was changed according to arrangement of conductors. We could find out arrangement of conductors at which electric stress is minimum. And this arrangement was satisfied with actual test conditions.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.6
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• pp.780-785
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• 2014

To assess the deterioration condition of stator insulation, diagnostic and AC dielectric strength tests were performed on five high voltage (HV) motors (2,000 HP, 6.6 kV) for boiler feed-water pump (BFP). Two HV motors for BFP were installed per unit. Following the long term rewinding program, the diagnostic test was performed on five 6.6 kV motors during the planning maintenance period. After completing diagnostic test, AC dielectric strength test was done on the stator windings of HV motors. The AC dielectric strength test was conducted at 15 kV for one minute. Dielectric strength test and diagnostics test results confirmed that the stator insulation was judged to be in serviceable condition in the five 6.6 kV motors.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.7
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• pp.802-808
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• 1992

To investigate degradation procedure and life time of the oxidized PE and the unoxidized PE, alternative voltage is applied to the CIGRE Method-II (CM-II) electrode system, which is loaded artificial void, and measures the distribution of partial discharging generation. From the results, the samples etched by oxidation had wide degradation area of dielectric strength. Furthermore, discharge starting voltage was shifted to low voltage, the discharge generation frequency was high and consequently, the quantity of mean charge becomes small. Also, life time of the oxdized sample is shortened according as the oxidation time is longer.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.12
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• pp.581-585
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• 2006

Macro interfaces between two different bulk materials which affect the stability of insulation system exist inevitably in the complex insulation system using in extra high voltage (EHV) electric devices. In this paper, Interface between epoxy and ethylene propylene diene terpolymer (EPDM) was selected as an interface in electrical insulation system and the AC dielectric strength of the interface was investigated. Air compress system was used to give pressure to the interface. Specimens were prepared in various ways to generate different surface conditions for each type of interface. Increasing interfacial pressure, decreasing surface roughness and spreading oil over surfaces improve the AC interfacial dielectric strength. Especially, the dielectric strength was saturated at certain interfacial pressure.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.3
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• pp.152-158
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• 2000

This paper deal with the experimental discussion about the impulse and AC dielectric strength of SF6 gas insulated transformer. Test sample is measured the dielectric breakdown voltage about modeling of the first and second section which is the weakest for surge voltage. The AC breakdown voltage is appeared 1.4 times than impulse breakdown voltage, so we can estimate that the impulse breakdown voltage is severe to AC breakdown voltage, and when the impulse is applied, in case of lmm tapping with Nomex paper, the characteristics of dielectric breakdown voltage is same to that in oil immersed transformer when SF6 gas pressure is 2.2kg/$cm^2$G.