• The Bulletin of The Korean Astronomical Society
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• v.30 no.1
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• pp.28.2-28.2
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• 2005

• The Bulletin of The Korean Astronomical Society
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• v.34 no.1
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• pp.155-155
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• 2009

• Journal of the Korean Mathematical Society
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• v.58 no.2
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• pp.501-523
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• 2021

We study the geometry of the moduli space of elliptic stable maps to projective space. The main component of the moduli space of elliptic stable maps is singular. There are two different ways to desingularize this space. One is Vakil-Zinger's desingularization and the other is via the moduli space of logarithmic stable maps. Our main result is a proof of the direct geometric relationship between these two spaces. For degree less than or equal to 3, we prove that the moduli space of logarithmic stable maps can be obtained by blowing up Vakil-Zinger's desingularization.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.9
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• pp.801-811
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• 2021

Lightning can deliver large amounts of energy to the aircraft in a short period of time, resulting in catastrophic consequence. In particular, lightning strikes accompanied by high temperature heat and current can damage aircraft surface and internal electronic equipment, seriously affecting flight safety. Lightning experiments to analyze this effect use a Component A waveform with a maximum current of 200 kA as specified in SAE ARP 5412B. However, the actual lightning occurs mostly below 35kA and lightning indirect tests are conducted by reducing waveforms to prevent damage to internal electronic equipment. In this study, we examine previous methods to plot the Component A reduced waveform and identify their limitations. We then propose a new method to plot the reduced waveform based on adjusting the correction factor of the aircraft lightning Component A waveform. Finally, the electromagnetic analysis software EMA3D was used to compare the internal induced current size reduction ratio of the internal cable harness of the EC-155B helicopter.

• Bulletin of the Korean Space Science Society
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• 2000.10a
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• pp.60-60
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• 2000

No Abstract, See Full Text

• Bulletin of the Korean Space Science Society
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• 1998.10a
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• pp.49-49
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• 1998

No Abstract.See Full-text

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.4
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• pp.110-117
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• 2006

• The Bulletin of The Korean Astronomical Society
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• v.24 no.1
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• pp.23-23
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• 1999

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.32 no.6
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• pp.96-103
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• 2004

Sought a set of component performance lines from experiment data or some data supplied in the engine manufacturer to improve the traditional scaling method and suggested a map scaling method that construct component performance lines newly using polynomial equations of MATLAB program. In this study, applied technique that is proposed newly to PT6A-62 that verified technique that is proposed newly using experiment data of small. size turboshaft engine, and is actuality aircraft engine. In identification of the component maps of the turboprop engine, the simulated performance using the proposed scaling method was compared with the real engine performance data and the performance using the traditional scaling method.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1890-1901
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• 2022

We have assessed the applicability of the thermal-hydraulic system analysis code, SPACE, to a small modular reactor called SMART. For the assessment, the experimental data from a scale-down integral-test facility, SMART-ITL, were used. It was conformed that the SPACE code unrealistically calculates the safety injection flow rate through the CMT and SIT during a small-break loss-of-coolant experiment. This unrealistic behavior was due to the overprediction of interfacial heat transfer at the steam-water interface in a vertically stratified flow in the tanks. In this study, a special thermal-hydraulic component model has been developed to realistically calculate the interfacial heat transfer when a strong non-equilibrium two-phase flow is formed in the CMT or SIT. Additionally, we developed a special heat structure model, which analytically calculates the heat transfer from the hot steam to the cold tank wall. The combination of two models for the tank are called the special component model. We assessed it using the SMART-ITL passive safety injection system (PSIS) test data. The results showed that the special component model well predicts the transient behaviors of the CMT and SIT.