• Journal of the Korean Data and Information Science Society
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• v.12 no.2
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• pp.47-55
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• 2001

Usually estimating the means is used for statistical inference. However depending the purpose of survey, sometimes totals will give the better and more meaningful in statistical inference than the means. Here in this study, we dealt with the unemployment population of small areas with using 4 different small area estimation methods: Direct, Synthetic, Composite, Bayes estimation. For all the estimates considered in this study, the average of absolute bias and men square error were obtained in the Monte Carlo Study which was simulated using data from 1998 Economic Active Population Survey in Korea.

• Journal of Welding and Joining
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• v.31 no.6
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• pp.32-36
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• 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.