• Journal of the Korean Data and Information Science Society
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• v.16 no.4
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• pp.759-768
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• 2005

K-means clustering has been widely used in many applications, such that pattern analysis, data analysis, market research and so on. It can identify dense and sparse regions among data attributes or object attributes. But k-means algorithm requires many hours to get k clusters, because it is more primitive and explorative. In this paper we propose a new method of k-means clustering using the grid-based representative value(arithmetic and trimmed mean) for sample. It is more fast than any traditional clustering method and maintains its accuracy.

• Proceedings of the Korean Statistical Society Conference
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• 2002.05a
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• pp.45-48
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• 2002

Consider the mean distance of Brownian motion on Riemannian manifolds. We obtain the first three terms of the asymptotic expansion of the mean distance by means of Stochastic Differential Equation(SDE) for Brownian motion on Riemannian manifold. This method proves to be much simpler for further expansion than the methods developed by Liao and Zheng(1995). Our expansion gives the same characterizations as the mean exit time from a small geodesic ball with regard to Euclidean space and the rank 1 symmetric spaces.

• Journal of the Korean Data and Information Science Society
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• v.13 no.1
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• pp.147-156
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• 2002

In this paper, we study the properties of the modified winsorized mean to estimate the mean of a two-truncation parameter population. Under some mild conditions, the estimator is found to be strongly consistent and asymptotically unbiased even though the sample is doubly type II censored.

• Korean Journal of Mathematics
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• v.23 no.4
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• pp.571-590
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• 2015

Let a, b, q be integers with q > 0. The homogeneous Dedekind sum is dened by $$\Large S(a,b,q)={\sum_{r=1}^{q}}\(\({\frac{ar}{q}}\)\)\(\({\frac{br}{q}}\)\)$$, where $$\Large ((x))=\{x-[x]-{\frac{1}{2}},\text{ if x is not an integer},\\0,\hspace{75}\text{ if x is an integer.}$$ In this paper we study the mean value of S(a, b, q) by using mean value theorems of Dirichlet L-functions, and give some asymptotic formula.

• Journal of the Korean Statistical Society
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• v.34 no.2
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• pp.99-107
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• 2005

In this paper we consider the asymptotic mean squared error of positive part James-Stein estimators. In the normal-normal example, estimators of the mean squared error of these estimators are provided which are correct asymptotically up to O($m^{-l}$). Asymptotic estimators of the MSE's which correct up to O($m^{-l}$) are also provide. Here, m denotes the number of strata. A simulation study is undertaken to evaluate the performance of these estimators.

• Bulletin of the Korean Mathematical Society
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• v.54 no.1
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• pp.17-28
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• 2017

In this paper, we deal with a class of mean-field backward stochastic differential equations (BSDEs) related to finite state, continuous time Markov chains. We obtain the existence and uniqueness theorem and a comparison theorem for solutions of one-dimensional mean-field BSDEs under Lipschitz condition.

• Communications for Statistical Applications and Methods
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• v.17 no.3
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• pp.391-411
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• 2010

For estimating the mean of a finite population, three classes of estimators using multi-auxiliary information with unknown means using two phase sampling in presence of non-response have been proposed with their properties. Asymptotically optimum estimator(AOE) in each class has been identified along with their mean squared error formulae. An empirical study is also given.

• Journal of Yeungnam Medical Science
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• v.8 no.1
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• pp.154-165
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• 1991

To establish the hematological reference values in the healthy adults visited our hospitals, following examination were done on 2823 persons by Coulter Counter Model S-plus II ; white blood cell count: (WBC), red blood cell count(RBC), hemoglobin(Hb), hematocrit(Hct), mean corpuscular volume (MCV), mean corpuscular hemoglobin(MCH), mean corpuscular hemoglobin concentration(MCHC), red cell distribution width(RDW), platelet, plateletcrit, mean platelet volume(MPV) and platelet distribution width(PDW). The following results are obtained. 1) Male, mean value of WBC ; $6,800{\pm}2,680(2SD)/{\mu}l$ Female, mean value of WBC ; $5,950{\pm}2,380(2SD)/{\mu}l$ 2) Male, mean value of RBC ; $428{\pm}60(2SD){\times}10^4/{\mu}l$ Female, mean value of WBC ; $415{\pm}56(2SD){\times}10^4/{\mu}l$ 3) Male, mean value of Hb ; $15.4{\pm}1.8(2SD)g/dL$ Female, mean value of Hb ; $13.0{\pm}1.6(2SD)g/dL$ 4) Male, mean value of Hct ; $45.3{\pm}5.0(2SD)%$ Female, mean value of Hct ; $38.2{\pm}4.6(2SD)%$ 5) Male, mean value of MCV ; $93.8{\pm}5.8(2SD)fL$ Female, mean value of MCV ; $92.2{\pm}7.4(2SD)fL$ 6) Male, mean value of MCH ; $31.8{\pm}2.2(250)pg$ Female, mean value of MCH ; $31.4{\pm}2.8(2SD)pg$ 7) Male, mean value of MCHC ; $34.0{\pm}1.2(2SD)%$ Female, mean value of MCHC ; $33.9{\pm}1.2(2SD)%$ 8) Male, mean value of RDW ; $12.7{\pm}1.0(2SD)%$ Female, mean value of RDW ; $12.6{\pm}1.4(2SD)%$ 9) Male, mean value of Platelet ; $242.9{\pm}87.8(2SD){\times}10^3/{\mu}l$ Female, mean value of Platelet ; $242.2{\pm}89.0(2SD){\times}10^3/{\mu}l$ 10) Male, mean value of Plateletcrit ; $0.201{\pm}0.076(2SD)%$ Female, mean value of Plateletcrit ; $0.204{\pm}0.076(2SD)%$ 11) Male, mean value of MPV ; $8.20{\pm}1.70(2SD)fl$ Female, mean value of MPV ; $8.36{\pm}1.82(2SD)fl$ 12) Male, mean value of PDW ; $16.1{\pm}0.8(2SD)%$ Female, mean value of PDW ; $16.0{\pm}0.8(2SD)%$.

• Korean Journal of Veterinary Service
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• v.39 no.3
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• pp.151-157
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• 2016

The present study was undertaken to clarify the changes in blood chemical values of indigenous Korean striped calves according to age. Blood samples were collected from 15 calves (8 females and 7 males) reared at the Gyeongsangbukdo Livestock Research Institute and the levels of various chemicals in serum were analyzed. The mean total protein, albumin and globulin concentration in calves increased from 2 weeks after birth, and the levels in females were higher than those in males at 8 weeks after birth. The mean glucose concentration increased significantly at 2 weeks after birth. The mean blood urea nitrogen concentration increased from 2 weeks after birth, whereas the mean creatinine concentration decreased significantly from 2 weeks after birth. The mean uric acid concentration increased gradually from 2 weeks after birth. The mean glutamic oxaloacetic transaminase and glutamic pyruvic transaminase concentration increased significantly from 2 weeks after birth. The mean total bilirubin concentration tended to decrease from 2 weeks after birth. The mean triglyceride, total cholesterol and high density lipoprotein cholesterol concentration increased significantly from 2 weeks after birth. In conclusion, the data obtained from this study may be valuable as a standard for interpreting results of biochemical analyses in indigenous Korean striped calves.

• Communications for Statistical Applications and Methods
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• v.18 no.4
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• pp.537-548
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• 2011

In this paper following Singh et al. (2008), we propose a modified ratio-product type exponential estimator to estimate the finite population mean $\={Y}$ of the study variable y in presence of non-response in different situations viz. (i) population mean $\={X}$ is known, and (ii) population mean $\={X}$ is unknown. The expressions of biases and mean squared error of the proposed estimators have been obtained under large sample approximation using single as well as double sampling. Some realistic conditions have been obtained under which the proposed estimator is more efficient than usual unbiased estimators, ratio estimators, product estimators and exponential ratio and product estimators reported by Rao (1986) and Singh et al. (2010) are found to be more efficient in many situations.