• Communications for Statistical Applications and Methods
• /
• v.7 no.1
• /
• pp.233-244
• /
• 2000

Confidence intervals for survival function give useful information about the lifetime distribution. In this paper we develop Edgeworkth expansions as approximation to the true and bootstrap distributions of normalized nonparametric maximum likelihood estimator of survival function in the Koziol-Green model and then use these results to show that the bootstrap approximations have second order accuracy.

• Communications for Statistical Applications and Methods
• /
• v.13 no.2
• /
• pp.343-358
• /
• 2006

The distributional properties of forecasts in an integer-valued time series model have not been discovered yet mainly because of the complexity arising from the binomial thinning operator. We propose two bootstrap methods to obtain nonparametric prediction intervals for an integer-valued autoregressive model : one accommodates the variation of estimating parameters and the other does not. Contrary to the results of the continuous ARMA model, we show that the latter is better than the former in forecasting the future values of the integer-valued autoregressive model.

• Journal of the Korean Statistical Society
• /
• v.31 no.3
• /
• pp.379-389
• /
• 2002

For two normal distribution with unknown means and unknown variances, a sequential procedure for estimating the difference of two normal means which satisfies both the coverage probability condition and the $\beta$-protection is proposed under some smoothness of variable imprecision function, and the asymptotic normality of the proposed stopping time after some centering and scaling is given.

• Communications for Statistical Applications and Methods
• /
• v.3 no.2
• /
• pp.119-127
• /
• 1996

In this paper, we derive the Hall-Wellner band and the equal precistion band for survival function based on Hjort when the data are randomly right censored. The bands ate illustrated and compared by applying them to data from a preoperative radiation therapy.

• Communications for Statistical Applications and Methods
• /
• v.11 no.3
• /
• pp.657-668
• /
• 2004

Permutation test has been applied for the QTL(quantitative trait loci) analysis and we selected a major locus. K -means clustering analysis, for the major DNA Marker mining of ILSTS035 microsatellite loci in Hanwoo chromosome 6, has been described. Finally, bootstrap testing method has been adapted to calculate confidence intervals and for finding major DNA Markers.

• Communications for Statistical Applications and Methods
• /
• v.11 no.3
• /
• pp.447-454
• /
• 2004

In this paper, we consider the bootstrap method to the interval estimation of the difference of quantiles of right censored data. We showed the validity of bootstrap method and compare with others with real data example. In simulation various resampling schemes for right censored data are also considered.

• Communications for Statistical Applications and Methods
• /
• v.3 no.2
• /
• pp.13-19
• /
• 1996

Cook's distance(Cook, 1997) is one of the most widely used influence measures to assess the influence of single observations or sets of observations in the linear regression model. After computing Cook(1977) suggested guidelines based on a confidence ellipsoid for the regression parameter ${\beta}$. In this paper, we suggest cutoff values for Cook's distance cia Monte Carlo simulation, and compare them with Cook's guidelines. An example based on a real data set is given.

• Child Health Nursing Research
• /
• v.13 no.3
• /
• pp.349-356
• /
• 2007

Purpose: This study was to done to develop a nursing intervention, Meridian massage and to investigate its effects on the infants' growth and sleep of infants and on role confidence and sensitivity in their mothers. Method: This study used a nonequivalent control group non-synchronized quasi experimental. Infants and mothers from Y health center were assigned to an experimental group (17) and control group (14). Meridian massage was given to infants by their mothers. Data were collected from August 11, 2005 to February 24, 2006. Infants in the experimental group had Meridian massage for 15 min per time, three times a week for 3 weeks. Result: Regarding growth, infants in the experimental group showed a statistical significant increase in weight and height compared to those in the control group. Sleeping well was also significant for infants in the experimental group compare to those in the control group. There was no signifiant difference in confidence in mothering role between the two groups. Sensitivity for the mothering role was significantly higher for mothers of infants in the experimental group compare to those in the control group. Conclusion: Meridian massage is an effective nursing intervention in improving infant growth and maternal-infant interaction.

• The Korean Journal of Applied Statistics
• /
• v.18 no.3
• /
• pp.607-615
• /
• 2005

Recently the interval estimation of a binomial proportion is revisited in various literatures. This is mainly due to the erratic behavior of the coverage probability of the will-known Wald confidence interval. Various alternatives have been proposed. Among them, Agresti-Coull confidence interval has been recommended by Brown et al. (2001) with other confidence intervals for large sample, say n $\ge$ 40. On the other hand, a noninformative Bayesian approach called Polya posterior often produces statistics with good frequentist's properties. In this note, an interval estimator is developed using weighted Polya posterior. The resulting interval estimator is essentially the Agresti-Coull confidence interval with some improved features. It is shown that the weighted Polys posterior produce an effective interval estimator for small sample size and a severely skewed binomial distribution.

• The Korean Journal of Applied Statistics
• /
• v.27 no.5
• /
• pp.833-842
• /
• 2014

Non-inferiority trials indicate whether the effect of an experimental treatment is not worse than an active control. Chen et al. (2006) and Kang (2010) proposed a test method for non-inferiority trials using confidence intervals. In this paper, we suggest a new nonparametric method using a confidence interval based on Wilcoxon rank-sum test and Hodges-Lehmann estimator of active control. A Monte-Carlo simulation study compares the type I error and the power of the proposed method with previous methods.