• Journal of the Korean Data and Information Science Society
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• 제15권3호
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• pp.523-529
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• 2004

In Korea, mathematics education has been changed according to the 7th national mathematics curriculum renovated by the Ministry of Education and Human Resources Development announcement in 1997. The education of probability and Statistics has been carried out as a part of this curriculum. We analyze and compare 3 kinds of mathematics textbooks for 10-12 grade students. Descriptions of random variable, sample variance and sample standard deviation, distribution of sample mean, and etc. which are on some textbooks, are misleaded in school education. We suggest the unbiased estimator of sample variance in textbooks and distributions of sample means with normal population assumption.

• International Journal of Reliability and Applications
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• 제1권2호
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• pp.123-131
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• 2000

This paper concerns with the consistent estimator for the fuzzy expectation of a random variable taking values in the space F($R^p$) of upper semicontinuous convex fuzzy subsets of $R^p$ with compact support. We introduce the concept of a fuzzy sample mean and show that the fuzzy sample mean is a strong consistent estimator for the fuzzy expectation. Some examples are given to illustrate the main result.

• Journal of the Korean Data and Information Science Society
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• 제20권5호
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• pp.887-894
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• 2009

The two-stage minimum risk point estimation of mean, the probability of success in a sequence of Bernoulli trials, is considered for the case where loss is taken to be symmetrized relative squared error of estimation, plus a fixed cost per observation. First order asymptotic expansions are obtained for large sample properties of two-stage procedure. Monte Carlo simulation is carried out to obtain the expected sample size that minimizes the risk and to examine its finite sample behavior.

• International Journal of Reliability and Applications
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• 제7권2호
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• pp.177-186
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• 2006

Typical confidence intervals for a mean or mean residual life (MRL) are centered about the mean or mean residual life. We discuss novel confidence intervals that produce statements like "we are 95% confident that the MRL function, e(t), is greater than a prespecified $\mu_o$ for all t in the interval [0, $\hat{\theta})$)" where $\hat{\theta}$ is determined from the sample data, confidence level, and $\mu_o$. Also, we can have statements like 'we are 95% confident that the MRL of population 1, namely $e_1$(t), is greater than the MRL of population 2, $e_2$(t), for all t in the interval [0, $\hat{\theta}$)" where $\hat{\theta}$ is determined from the sample data and confidence level. We illustrate these one and two sample confidence intervals on internal bonds (tensile strengths) for an important modem engineered wood product, called medium density fiberboard (MDF), used internationally.

• 대한간호학회지
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• 제31권2호
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• pp.268-278
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• 2001

Many women in the world have suffered from anemia produced by menstruation, pregnancy and delivery. In the theory of oriental medicine, a sour taste is believed to have a tonic effect on the blood. Thus this paper is to investigate the effect of sour tastes on the improvement in anemia-induced female mice, using citric acid and Fructus schizandrae(五味子). The method used in this experiment was the change of RBC, WBC, Hemoglobin, Hematocrit, Fe, and TIBC in the blood of female mice who were fed citric acid and Fructus schizandrae(五味子). The results obtained were as follows ; 1. Compared with the control group (anemia- induced group without treatment), the mean number of RBC in the blood of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae (五味子) 500mg/kg. 2. Compared with the control group (anemia- induced group without treatment), the mean number of WBC in the blood of mice was not significantly larger in both sample groups fed citric acid and Fructus schizandrae(五味子). 3. Compared with the control group (anemia- induced group without treatment), the mean number of Hemoglobin in the blood of mice was significantly larger only in evaluating the change of the sample group fed Fructus schizandrae(五味子). 4. Compared with the control group (anemia- induced group without treatment), the mean percentage of Hematocrit in blood of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg and sample group fed Fructus schizandrae(五味子) 250mg/kg for 3days. 5. Compared with control group (anemia- induced group without treatment), the mean volume of Fe in serum of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg. 6. Compared with control group (anemia- induced group without treatment), the mean TIBC in serum of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg and sample group fed Fructus schizandrae(五味子) 250mg/kg for 7days. According to these results, a sour taste is presumed to have a general tonic effect on anemia, but more study must be taken on the effects of citric acid in improving female anemia.

• Communications for Statistical Applications and Methods
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• 제7권2호
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• pp.447-456
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• 2000

In this paper, we considered three methods for outlier identification sample surveys. First, we studied method of handling and adjusting outliers in normal population. Second, we studied existing methods using mean, maximum and minimum and proposed a test using of median which well reflects characteristic of data regardless of sampling distribution. Finally, we showed our test using median works better than Dixon and mean test through simulation.

• Communications for Statistical Applications and Methods
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• 제7권1호
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• pp.179-198
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• 2000

We consider the problem of comparing the mean vectors of two multivaiate populations, We focus on testing hypotheses concerning two multivariate mean vectors by use of MINITAB, For the cases of small sample and large sample MINITAB programs and outputs are presented for solving staistical problems. The MiniTAB programs made in this paper are saved as macro files and thus can be conveniently used for solving another problems.

• Journal of the Korean Statistical Society
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• 제33권3호
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• pp.323-337
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• 2004

This article coined a general class of estimators for various measures in normal population when some' a priori' or guessed value of standard deviation a is available in addition to sample information. The class of estimators is primarily defined for a function of standard deviation. An unbiased estimator and the minimum mean squared error estimator are worked out and the suggested class of estimators is compared with these classical estimators. Numerical computations in terms of percent relative efficiency and absolute relative bias established the merits of the proposed class of estimators especially for small samples. Simulation study confirms the excellence of the proposed class of estimators. The beauty of this article lies in estimation of various measures like standard deviation, variance, Fisher information, precision of sample mean, process capability index $C_{p}$, fourth moment about mean, mean deviation about mean etc. as particular cases of the proposed class of estimators.

• 한국경영과학회지
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• 제31권1호
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• pp.15-24
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• 2006

In simulation input modeling, it is important to identify a probability distribution to represent the input process of interest. In this paper, an appropriate sample size is determined for parameter estimation associated with some typical probability distributions frequently encountered in simulation input modeling. For this purpose, a statistical measure is proposed to evaluate the effect of sample size on the precision as well as the accuracy related to the parameter estimation, square rooted mean square error to parameter ratio. Based on this evaluation measure, this sample size effect can be not only analyzed dimensionlessly against parameter's unit but also scaled regardless of parameter's magnitude. In the Monte Carlo simulation experiments, three continuous and one discrete probability distributions are investigated such as ; 1) exponential ; 2) gamma ; 3) normal ; and 4) poisson. The parameter's magnitudes tested are designed in order to represent distinct skewness respectively. Results show that ; 1) the evaluation measure drastically improves until the sample size approaches around 200 ; 2) up to the sample size about 400, the improvement continues but becomes ineffective ; and 3) plots of the evaluation measure have a similar plateau pattern beyond the sample size of 400. A case study with real datasets presents for verifying the experimental results.

• 응용통계연구
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• 제7권2호
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• pp.21-34
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• 1994

본 논문에서 대기체계 M/M/1에서 평균 도착시간간격 $\theta$에 대한, 평형상태에서 평균시스템시간 (Steady State Mean System Time) W의 민감도 $dW/d\theta$를 표본통로(Sample Path)를 관찰하므로서 얻을 수 있는 방안을 제시하였으며, 평형상태에서 시스템 내에 고객이 k명 있을 확률, 즉 극한 확률(Limiting Probability) $P_k$의 민감도 $dP_k/d\theta$에 대해서도 유사한 결과를 얻었다. 또한 두 경우 모두 민감도의 추정값이 IPA(Infinitesimal Perturbation Analysis) 추정값과 그 이외의 요인에 의한 값의 합으로 명확히 표시됨을 보임으로서 IPA 추정값이 일반적으로 적용될 수 없음을 확인하였다.