• 응용통계연구
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• 제19권3호
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• pp.395-406
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• 2006

임상시험 연구나 역학 연구에서 환자들의 예후는 흔히 생존을 추정을 통해 수량화 되곤 한다. 하지만 코호트 분석이나 완전분석에 의한 생존율 추정량들은 수년 전에 진단된 환자에 크게 의존하기 때문에 실제 생존율보다 더 낮게 추정하곤 한다. 본 연구에서는 최근의 생존정보를 잘 반영하는 생존을 추정을 위해 기간분석 방법을 통한누적한계 추정량을 제안하였고, 그 방법을 1993년 1월-1997년 12월 사이에 조사된 서울시 암등록 자료(Ahn등, 2002)에 적용하여 결과를 고찰하였다.

• Journal of the Korean Statistical Society
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• 제26권3호
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• pp.299-308
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• 1997

In the simple linear regression model Y = .alpha.$_{0}$ + .beta.$_{0}$Z + .epsilon. under the right censorship of the response variables, the estimation of the mean lifetime E(Y) is an interesting problem. In this paper we propose a method of estimating E(Y) based on the observations modified by the arguments of Buckley and James (1979). It is shown that the proposed estimator is consistent and our proposed procedure in the simple linear regression case can be naturally extended to the multiple linear regression. Finally, we perform simulation studies to compare the proposed estimator with the estimator introduced by Gill (1983).83).

• International Journal of Quality Innovation
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• 제6권2호
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• pp.31-45
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• 2005

The target costing technique, mathematically discussed by Sauers, only uses the $C_p$ index along with Taguchi loss function and ${\bar{X}}-R$ control charts to set up goal control limits. The new specification limits derived from Taguchi loss function is linked through the $C_p$ value to ${\bar{X}}-R$ control charts to obtain goal control limits. This study further considers the reflected normal loss function as well as the $C_{pk}$ index along with its lower confidence interval in forming goal control limits. With the use of lower confidence interval to replace the point estimator of the $C_{pk}$ index and reflected normal loss function proposed by Spiring to measure the loss to society, this modified and improved target costing technique would become more robust and applicable in practice. Finally, an example is provided to illustrate how this modified and improved target costing technique works.

• Journal of the Korean Data and Information Science Society
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• 제28권4호
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• pp.947-955
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• 2017

A competing risk analysis has been applied when subjects experience more than one type of end points. Geskus (2011) showed three types of estimators of CIF are equivalent under left truncated and right censored data. We extend his approach to an interval censored competing risk data by using a modified risk set and evaluate their performance under several sample sizes. These estimators show very similar results. We also suggest a test statistic combining Sun's test for interval censored data and Gray's test for right censored data. The test sizes and powers are compared under several cases. As a real data application, the suggested method is applied a data where the feasibility of the vaccine to HIV was assessed in the injecting drug uses.