• Journal of the Korean Data and Information Science Society
• /
• 제12권2호
• /
• pp.47-55
• /
• 2001

직접(direct) 추정법, 합성(synthetic) 추정법, 복합(composite) 추정법, 베이즈(Bayes) 추정법 등 소지역 추정법들의 효율성을 비교, 분석하고자 '98 경제활동 인구조사에서 경기도의 실제 자료를 이용하여 각 시부지역의 실업자수 추정값의 편의(bias)와 평균제곱 오차(MSE)를 모의실험을 통해 계산하였다.

• Journal of Welding and Joining
• /
• 제31권6호
• /
• pp.32-36
• /
• 2013

The large-scale structures have the possibility that there are defects such as cracks due to stress concentration caused by geometric discontinuities in the structure. In this respect, the assessment of fatigue life and the development of structural health monitoring(SHM) are very important. Fatigue design of structure is typically accomplished either using a set of stress cycle (S-N) data obtained from fatigue tests or using the fracture mechanics approach. The stress intensity factor(SIF) is required for the estimation of fatigue crack propagation life from the linear elastic fracture mechanics (LEFM) perspective. In this study, Macro Fiber Composie(MFC) sensor for the measurement of SIF of two dimensional cracks is used. The SIF based on the piezoelectric constitutive law and fracture mechanics are calculated. The measured values of the SIF are later used for the prediction of the crack propagation life. In this study, the measured value of the SIF and the fatigue life are compared with the theoretical results.