• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.597-602
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• 1998

The composite systems, consisting of R/C Columns-Steel Beams, are reasonable structures because of their constructional and economical advantages, workability and so on. But, it is difficult to apply the composite systems to actual design due to material dissimilarity and complicate stress flow in the connection. This study aims to propose the hybrid beam-column connection system with structural tee and through experimental research make clear the shear and moment resistance capacity and stress transfer mechanism.

• Journal of the Korean Ceramic Society
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• v.29 no.12
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• pp.949-955
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• 1992

R-curves, fracture resistance (KR) as a function of crack extension (Δa), of a gas-pressure sintered monolithic Si3N4 were determined by controlled flaw/strength technique. Rising R-curve behavior was observed, confirming the operation of microstructural toughening process during crack growth. The R-curve parameters, k and m in the equation, KR=k(Δa)m, were determined to 30.301 and 0.1146, respectively. Microstructural observation of growing crack revealed that the bridging in the crack wake by unbroken ligament of large elongated ${\beta}$-grains was the mechanism primarily for the rising R-curve behavior.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1997.10a
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• pp.219-224
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• 1997

In surface grinding, the contact between the grinding wheel and the workpiece introduces heat and resistance, which restrict the self-dressing of the grits and result in burrs and cracks on the workpiece. Therefore, before or during th grinding wheel for more accurate performance. In order to determine the dressing time monitoring method of grinding wheel in surface grinding, a three-dimensional computer simulation of the grinding operation has been attempted based on the contact mechanism and surface-shaping system between the grinding wheel and the workpiece. The optimal dressing time is determined based on the amount of the grain wear and work surface roughness.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.228.3-228
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• 2005

• Sleep Medicine and Psychophysiology
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• v.10 no.2
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• pp.88-92
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• 2003

Sleep-disordered breathing (SDB), including snoring, sleep apnea and upper airway resistance syndrome are common problems in children. The pathophysiological mechanism of SDB in children is unclear but may include hypoxemia and changes in sleep architecture. Children with SDB show reduced neurocognitive function, and memory and attentional capacity. Furthermore, these children show increased problematic behaviour and reduced school performance. Whether early recognition and treatment of SDB in children may improve neurocognitive function and school performance remains to be fully evaluated in the future.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.03a
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• pp.76-79
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• 1998

High temperature plastic deformation behavior of Al 6061 alloy was characterized by hot torsion test. The Al 6061 alloy deformed continuously in the temperature range of 400∼550$^{\circ}C$, and strain rate range of 0.05∼5/sec. The softening mechanism of Al 6061 alloy was dynamic recrystallization and identified by hyperbolic sine law and zener-Hollmon parameter. The evolution of grain size and deformation resistance were calculated by the relationships of deformation variables.

• BMB Reports
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• v.33 no.1
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• pp.1-36
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• 2000

Acetohydroxyacid synthase (EC 4.1.3.18) catalyses the first reaction in the pathway for synthesis of the branched-chain amino acids. The enzyme is inhibited by several commercial herbicides and has been subjected to detailed study over the last 20 to 30 years. Here we review the progress that has been made in understanding its structure, regulation, mechanism, and inhibition.

• Journal of Welding and Joining
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• v.12 no.2
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• pp.39-48
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• 1994

In comparison to the conventional brazing, laser welding of ceramics has advantages of direct bonding without filler material, which causes the thermal stress due to the differences of thermal expansion coefficients. In pulse-mode, laser welding of dispersion ceramic having high thermal resistance is possible at relatively low preheating temperature of $1300^{\circ}C$ In CW-mode, alumina can be welded at high preheating temperature $1500^{\circ}C$ under the condition of low feed rate of 500 mm/min, respectively. Further studies on developing mechanism of pores in the bead during laser welding of ceramics is required.

• Proceedings of the Korean Magnestics Society Conference
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• 2002.12a
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• pp.120-120
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• 2002

In past years, theoretical controversy involving a realistic and physical mechanism that leads to large magnetic entropy change as a large magneto-caloric effect in colossal magneto-resistance (CMR) materials had been left as an open question. Thus it is desirable to clarify this problem. (omitted)

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.09a
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• pp.193-215
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• 2003

Fracture Mechanism of Flip Chip Electromigration Failure - Mostly caused by Cathode Depletion at the UBM/Solder Interface Guideline to Increase Electromigration Resistance Material Selection: Sn/Ag(/Cu) > Pb/63Sn Cu UBM > Ni UBM (but, Solder Material combination) UBM Design: thick UBM is preferable (but, Stress Issue) Pad open/UBM size: as large as possible (but, pad size & pitch limit)