• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.525-531
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• 2010

In this paper, a mobile quiz system using SMS has been developed, which can be conveniently used on the spot of education. The system immediately not only provides each individual student with the results of his/her quizzes but also a instructor with the statistics of the results by SMS. Field tests of the quiz system have shown that it can be effectively used as a good teaching tool for teachers getting immediate feedback from participants in the lecture and adjusting teaching level as well as for inducing more interest in learning from participants and raising their concentration on the class.

• Tribology and Lubricants
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• v.34 no.1
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• pp.9-15
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• 2018

Modern high-performance automotive turbochargers (TCs) implement ceramic hybrid angular contact ball bearings in series with squeeze film dampers (SFDs) to enhance transient responses, thereby reducing the overall emission levels. The current study predicts the rotordynamic responses of the commercial automotive TCs (compressor wheel diameter = ~53 mm, turbine wheel diameter = ~43 mm, and shaft diameter at the bearing locations = ~7 mm) supported on ball bearings and SFDs for various design parameters of SFDs, including radial clearance, axial length, lubricant viscosity, and rotor imbalance conditions (i.e., amplitudes and phase angles) while increasing rotor speed up to 150 krpm. This study validates the predictive rotor finite element model against measurements of mass, polar and transverse moments of inertia, and free-free mode natural frequencies and mode shapes. A nonlinear rotordynamic model integrates nonlinear force coefficients of SFDs to calculate the transient responses of the TC rotor-bearing system. The predicted results show that SFD radial clearances, as well as phase angles of rotor imbalances, have the paramount effect on the dynamic responses of TC shaft motions.

• The Mathematical Education
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• v.3 no.8
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• pp.11-12
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• 1965

• KAPE Magazine
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• s.230
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• pp.7-9
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• 2015

• KAPE Magazine
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• s.216
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• pp.10-11
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• 2014

• 베이커리
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• no.12 s.413
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• pp.125-127
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• 2002

올해 '퀴즈노스'와 같은 외국 샌드위치 브랜드의 국내 상륙이 잇따르는 등 샌드위치 업계에 관심이 집중되고 있다. 새로운 식도락 문화를 창출하고 있는 샌드위치 시장을 프랜차이즈 업체들의 향방을 통해 짚어본다.

• School Mathematics
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• v.1 no.2
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• pp.699-721
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• 1999

• The Mathematical Education
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• v.33 no.2
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• pp.221-233
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• 1994

• Monthly Duck's Village
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• s.110
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• pp.82-85
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• 2012

• Journal of Power System Engineering
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• v.7 no.4
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• pp.44-48
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• 2003

Alumium alloys casting are gaining increased acceptance in the automotive and electronic industeries and squeeze casting is the most efficient method of manufacturing such mass produced parts. This study has been investigated the microstructures and mechanical properties of Al-7.0Si-0.4Mg(AC4C)alloy fabricated by squeeze casting process for development of Engine Mountain Bracket. The microstructure of squeeze casted specimen were composed of eutectic structure Alumimim solid solution and $Mg_2Si$ precipitates. The tensile strength of as-solid solution treatment Al-7.0Si-0.4Mg alloy revealed 2985MPa. It was found that Al-7.0Si-0.4Mg alloy have good aging hardening effect results are presented to show the validity of the control method.