In order to improve the seismic performance of structures, friction pendulum system (FPS) is the most commonly used seismic isolation device in addition to lead rubber bearing (LRB) in high seismicity area. In a nuclear power plant (NPP) with a large self weight, it is necessary to install a large number of seismic isolation devices, and the position of the center of rigidity varies depending on the arrangement of the seismic isolation devices. Due to the increase in the eccentricity, which is the difference between the center of gravity of the nuclear structure and the center of stiffness of the seismic isolators, an excessive seismic response may occur which could not be considered at the design stage. Three different types of eccentricity models (CASE 1, CASE 2, and CASE 3) were used for seismic response evaluation of seismically isolated NPP due to the increase of eccentricity (0%, 5%, 10%, 15%). The analytical model of the seismic isolation system was compared using the equivalent linear model and the bilinear model. From the results of the seismic response of the seismically isolated NPP with increasing eccentricity, it can be observed that the effect of eccentricity on the seismic response for the equivalent linear model is larger than that for the bilinear model.

본 논문은 최고경영자(Chief Executive Officer, CEO)의 특성이 기업의 위험관리 의사결정에 어떤 영 향을 미치는지를 분석하고자 하였다. 최고경영자의 특성을 나타내는 변수로 나이와 취득전공을 선정하여 2008년 금융위기 전후로 파생상품을 이용한 제조기업들을 대상으로 구조화파생상품을 이용한 기업들만의 차별화된 특성을 분석하였다. 연구결과는 다음과 같다. 일반적으로 CEO의 나이가 많아질수록 보수적 이고 안정적인 의사결정을 한다는 첫 번째 가설을 검증한 결과, CEO의 나이는 복잡한 구조화파생상품을 이용하는데 별다른 영향을 미치지 못하는 것으로 나타났다. 상경관련 전공자가 파생상품을 더 잘 이해하고 복잡한 구조화파생상품이 위험관리용으로 적절하지 않기에 더 적게 사용할 것이라는 두 번째 가설을 검증한 결과, 비상경계 CEO의 파생상품 이용정도가 상경계 CEO보다 더 높은 것으로 나타나서 가설을 지지하는 것으로 나타났다.

Flame arrestor as end of line flame arrester for endurance burning prevents a light-back at deflagration and stabilized burning (during and after endurance burning) of potentially explosive vapor-air and gas-air mixtures at the end of vent pipes. In a flame arrestor, spring is an important part. The spring load as well as the spring's elasticity determine when the hood is opened. In addition, the spring have to work in high temperature condition due to gas burning. Therefore, it is necessary to analyze mechanical load and elasticity of spring when gas is burned. Based on the dynamic calculation on working process of a specific flame arrestor, analysis of spring is taken. A three dimensional model for spring burned in flame arrestor by using CFD simulation. Results of the CFD analysis are input in FEM simulation to analyze structure of the spring. The simulation results can predict and estimate the spring’s load and elasticity at variation of the spring’s deflection. Moreover, the obtained result can provide makers with references to optimize design of spring as well as flame arrestor.