• Journal of the Korean Statistical Society
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• 제22권1호
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• pp.27-37
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• 1993

Since the analytic expression for a diagnostic in the logistic regression model is not available, one-step estimation is often used by a case-deletion point of view. In this paper, infinitesimal perturbation approach is used, and it is shown that the scale transformation of infinitesimal perturbation approach is eventually equal to the weighted perturbation of local influence approach and the replacement measure. Also, multiple cases deletion for the masking effect is considered.

• Communications for Statistical Applications and Methods
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• 제16권5호
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• pp.813-820
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• 2009

In this paper, we review the utility-based generalization of the Shannon entropy and Kullback-Leibler information measure as the U-entropy and the U-relative entropy that was introduced by Friedman et al. (2007). Then, we derive some relations between the U-relative entropy and other information measures based on a parametric family of utility functions.

• Journal of the Korean Statistical Society
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• 제31권4호
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• pp.447-458
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• 2002

The influence of observations in the equicorrelation model is investigated using the local influence approach when all parameters or subsets of parameters are of interest. When a parameter of interest is scalar, an analytical form of the local influence measure can be found. We will derive a measure for identifying observations that have a large influence on the test of fitting the equicorrelation model. An example is given for illustration.

• Communications for Statistical Applications and Methods
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• 제11권3호
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• pp.563-574
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• 2004

Slope rotatability of response surface designs is a desirable property when we are interested in estimating slopes of response surfaces. In this paper, we derive a simplified measure of slope rotatability from new viewpoints for response surface designs that are frequently used in response surface methodology.

• 응용통계연구
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• 제16권1호
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• pp.151-167
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• 2003

두 확률변수의 연관성을 측정하는 측도는 많이 있으나, 이러한 측도는 같은 유형인 변수들 간의 관계를 측정하기 위한 것으로 여러 가지 유형의 변수들이 혼재되어 있는 혼합자료에서 사용하기는 곤란하다 본 논문에서는 두 확률변수의 독립성 검정을 통해 구한 p-값으로 혼합자료에서 사용될 수 있는 새로운 연관성 측도를 구하였으며, 이렇게 구하여진 연관성 측도가 혼합자료에서 변수들 간의 연관성을 비교하는데 유용하게 사용될 수 있음을 보였다.

• 응용통계연구
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• 제34권4호
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• pp.523-536
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• 2021

두 확률변수의 연관성을 측정하는 측도는 많이 있으나, 이러한 측도는 같은 유형인 변수들 간의 관계를 측정하기 위한 것으로 여러 가지 유형의 변수들이 혼재되어 있는 혼합자료에서 사용하기는 곤란하다. 본 논문에서는 두 확률변수의 독립성 검정을 통해 구한 p-값으로 혼합자료에서 사용될 수 있는 새로운 연관성 측도를 구하였으며, 이렇게 구하여 진 연관성 측도가 혼합자료에서 변수들 간의 연관성을 비교하는데 유용하게 사용될 수 있음을 보였다.

• 한국대기환경학회지
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• 제23권4호
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• pp.449-456
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• 2007

Dispersion coefficient preprocessing schemes have been examined to improve plume dispersion model performance in complex coastal areas. The performances of various schemes for constructing the sigma correction order were evaluated through estimations of statistical measures, such as bias, gross error, R, FB, NMSE, within FAC2, MG, VG, IOA, UAPC and MRE. This was undertaken for the results of dispersion modeling, which applied each scheme. Environmental factors such as sampling time, surface roughness, plume rising, plume height and terrain rolling were considered in this study. Gaussian plume dispersion model was used to calculate 1 hr $SO_2$ concentration 4 km downwind from a power plant in Boryeung coastal area. Here, measured data for January to December of 2002 were obtained so that modelling results could be compared. To compare the performances between various schemes, integrated scores of statistical measures were obtained by giving weights for each measure and then summing each score. This was done because each statistical measure has its own function and criteria; as a result, no measure can be taken as a sole index indicative of the performance level for each modeling scheme. The best preprocessing scheme was discerned using the step-wise method. The most significant factor influencing the magnitude of real dispersion coefficients appeared to be sampling time. A second significant factor appeared to be surface roughness, with the rolling terrain being the least significant for elevated sources in a gently rolling terrain. The best sequence of correcting the sigma from P-G scheme was found to be the combination of (1) sampling time, (2) surface roughness, (3) plume rising, (4) plume height, and (5) terrain rolling.

• Toxicological Research
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• 제30권3호
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• pp.185-191
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• 2014

Statistical methods are frequently used in toxicology, yet it is not clear whether the methods employed by the studies are used consistently and conducted based on sound statistical grounds. The purpose of this paper is to describe statistical methods used in top toxicology journals. More specifically, we sampled 30 papers published in 2014 from Toxicology and Applied Pharmacology, Archives of Toxicology, and Toxicological Science and described methodologies used to provide descriptive and inferential statistics. One hundred thirteen endpoints were observed in those 30 papers, and most studies had sample size less than 10, with the median and the mode being 6 and 3 & 6, respectively. Mean (105/113, 93%) was dominantly used to measure central tendency, and standard error of the mean (64/113, 57%) and standard deviation (39/113, 34%) were used to measure dispersion, while few studies provide justifications regarding why the methods being selected. Inferential statistics were frequently conducted (93/113, 82%), with one-way ANOVA being most popular (52/93, 56%), yet few studies conducted either normality or equal variance test. These results suggest that more consistent and appropriate use of statistical method is necessary which may enhance the role of toxicology in public health.

• 응용통계연구
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• 제32권1호
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• pp.15-27
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• 2019

데이터에 대한 신뢰도는 측정결과의 전반적인 일관성을 의미한다. 이러한 신뢰도는 분석결과에 영향을 미치므로 측정된 데이터에 대한 신뢰도를 평가하는 방법은 지속적으로 연구되고 있으며, 일반적으로 크론바흐의 알파 계수(Cronbach's ${\alpha}$ coefficient)나 급내상관계수(intraclass correlation coefficient; ICC) 등이 신뢰도 평가에 주로 이용되고 있다. 그러나 특정 개체를 입체적으로 표현하기 위해 3차원 좌표로 구성되는 데이터에 대해서는 기존의 신뢰도 평가 척도를 적용할 수 없다. 따라서 본 연구에서는 통계적 형상분석을 이용하여 측정된 3차원 좌표로부터 개체들의 형상정보를 추출하고 그들의 형상변동을 분해하여, 3차원 형상에 대한 신뢰도를 평가할 수 있는 측도를 제안하고자 한다.

• Communications for Statistical Applications and Methods
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• 제10권2호
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• pp.341-352
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• 2003

Collecting data through experiment, the observers are an import source of measurement error and the inference on the measure of agreement, say kappa, is necessary. The models commonly used are complicated general mixture model, which have many nuisance parameters. Orthogonalization of parameters reduce the effect of nuisance parameter. Orthogonalization of estimating function gives the same effect as the parameter orthogonalization. In this study, the method for orthogonalization of estimating equation is studied and applied to the Beta-binomial model to examine the properties of the estimate of kappa. As a result, the likelihood function is insensitive to the change of the nuisance parameter and bias is smaller than the result of m.1.e. when kappa has extreme values