S-Space College of Agriculture and Life Sciences (농업생명과학대학) Research Institute of Agriculture and Life Sciences (농업생명과학연구원) Journal Papers (저널논문_농업생명과학연구원)
Sensitivity of censored data analysis to determine the characteristic value of structural timber
- Pang, Sung-Jun; Lee, Hyeon-Jeong; Ahn, Kyung-Sun; Oh, Jung-Kwon
- Issue Date
- Springer Open
- Journal of Wood Science. 2020 May 24;66(1):39
- Characteristic value; Structural timber; Tensile strength; Censored data; Maximum likelihood estimation; Kaplan–Meier method
- In structural timber tests, unintended failure mechanisms occur frequently in specimens and their results are called censored data. There are two censored data analysis: censored maximum likelihood estimation (CMLE) and Kaplan–Meier (KM) method. In this study, the precision of the censored data analysis was investigated to determine the characteristic value, 5th percentile value, of the structural timber. The results show that (1) the 5th percentile value was underestimated by ordinary data analysis methods; maximum likelihood estimation (MLE) and Order statistics. (2) CMLE with 30% lower tail censored data and KM method provided much more precise 5th percentile value. (3) The amount of under-measurement (5 MPa, 10 MPa, and 15 MPa in this simulation study) did not show significant effect on the 5th percentile determination in CMLE and KM method, but the proportion of censored data (percentage of unintended failure specimen; 10%, 20%, 30%, and 40%) affected the determination of 5th percentile value. (4) CMLE with 30% lower tail censored data and KM method showed good agreement in case that the data included unintended failure data up to 20%.