Papers by Author: Dong Jo Kim

Abstract: The fatigue vulnerability estimation method including the effects induced by the corrosion rate and the traffic variation with time has been proposed to evaluate the reduction of fatigue strength in steel bridge members. A fatigue limit state function considering corrosion and traffic variation is established to determine whether the steel bridge members have been damaged by both corrosion and fatigue or not. Monte-Carlo simulation is used for reliability analysis which provides the data used to obtain fatigue vulnerability curves. The results show that the damage accumulation induced by fatigue in steel bridges could be assessed by fatigue vulnerability curve considering influences of corrosion and traffic variation.

Abstract: Using a thermally-crosslinkable organosiloxane-based organic-inorganic hybrid material, solution-processable gate dielectric layer for organic thin-film transistors (OTFTs) have been fabricated. The hybrid dielectric was synthesized by the sol-gel process. The surface of the prepared dielectric was modified by self-assembled monolayers (SAMs) treatment using wet chemical method. Prior to surface modification, the chemical inertness of prepared dielectric was investigated by immersing into various solvents such as toluene, acetone, isopropyl alcohol, and DI-water. The existence of SAMs on the surface of dielectric was confirmed by measuring current density-electric field characteristics and it was observed that surface morphology of SAMs-treated hybrid dielectric was very smooth.