• Journal of the Korean Data and Information Science Society
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• 제7권1호
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• pp.69-78
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• 1996

Consider a natural model for stochastic flow systems is Brownian motion, which is Brownian motion on the positive real line with constant drift and constant diffusion coefficient, modified by an impenetrable reflecting barrier at $x_{0}$. In this paper, we investigate the joint distribution functions and study on the distribution of the first-passage time. Also we find out the distribution of ${\mu}-RBMPx_{0}$.

• Journal of the Korean Data and Information Science Society
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• 제28권4호
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• pp.875-888
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• 2017

The Rayleigh distribution has been commonly used in life time testing studies of the probability of surviving until mission time. We focus on a reliability function of the Rayleigh distribution and deal with prior distribution on R(t). This paper is an effort to obtain Bayes estimators of rayleigh distribution with three different prior distribution on the reliability function; a noninformative prior, uniform prior and inverse gamma prior. We have found the Bayes estimator and predictive density function of a future observation y with each prior distribution. We compare the performance of the Bayes estimators under different sample size and in simulation study. We also derive the most plausible region, prediction intervals for a future observation.

• 유통과학연구
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• 제15권9호
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• pp.17-26
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• 2017

Purpose - This study aims to present ways to secure capable employees by examining key factors of internal marketing applicable to the jewelry distribution business and analyzing the relations among organizational commitment, job satisfaction, and turnover intentions among employees who play important roles in jewelry distributors. Research Design, data, and methodology - To examine these research models, samples were collected from 210 individuals working in jewelry distribution companies. The analysis was conducted by the use of a questionnaire method among employees in jewelry distribution companies. SPSS 18.0 were utilized for data analysis. Results - Among internal marketing components of jewelry distribution companies, the two factors - management support and reward system - have positive (+) effect on organizational commitment and while internal communication and education/training have negative (-) effect on employees' turnover intention. Jewelry distribution company employees' job satisfaction and organizational commitment have negative (-) effect on their turnover intention. Conclusions - This is an exploratory study that aims to find out ways to prevent employee turnover in the perspective of jewelry distribution companies' organizational measure - internal marketing. The future study needs to present more sophisticated strategies of internal marketing based on in-depth analysis of specific causes that make employees at jewelry distribution companies leave the occupations.

• 한국지하수토양환경학회지:지하수토양환경
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• 제23권1호
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• pp.41-53
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• 2018

Comprehensive statistical analysis for the 127 groundwater monitoring stations in Jeju Island during 2005~2015 was carried out for the re-establishment of management groundwater level. Three probability distribution functions such as normal distibution, GEV (General Extreme Value) distribution, and Gumbel distribution were applied and the maximum likelihood method was used for parameter estimation of each distribution. AIC (Akaike information criterion) was calculated based on the estimated parameters to determine the proper probability distribution for all 127 stations. The results showed that normal distribution and Gumble distribution were found in 11 stations. Whereas GEV distribution were found in 105 stations, which covered most of groundwater monitoring stations. Therefore, confidence levels should be established in accord with the proper probability distribution when groundwater level management is determined.

• 유통과학연구
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• 제19권8호
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• pp.5-12
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• 2021

Purpose: The purpose of this paper is to analyze and examine the issues that are directly associated with the United States COVID-19 vaccine distribution and its strategies so that other countries may learn from it and develop sound distribution strategies. Research design, data and methodology: This paper has applied both historical and narrative models to review, identify, and analyze existing literatures to assess the United States' vaccine distribution strategy. Results: Distribution strategy developed by the United States seems to have focused heavily on the basic tenets of physical distribution, i.e., transportation, warehousing, inventory, and large-venue mass-vaccination sites, and the strategy seems to have been successful when looking only at the physical tenets of distribution. However, the analysis indicates that the distribution strategy has not either focused on or included the major activities of distribution, such as inward and outward communication, information, and customer satisfaction. Conclusions: The countries that are currently developing or implementing COVID-19 vaccine distribution strategy should review and learn from the United States' vaccine distribution strategy and its implementation. The countries should include and address all the activities of distribution, including inward and outward communication, information, and customer satisfaction to achieve their vaccination goals, minimize confusion, reduce wasting of doses and vaccine desserts, and improve vaccination rates.

• Journal of the Korean Data and Information Science Society
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• 제7권1호
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• pp.119-127
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• 1996

The concepy of positive aging describles the adverse effects of age on the lifetime of units. Various aspects of this concepts are described in terms of conditional probability distribution of residual life times, failure rates, equilibrium distributions, etc. In this paper we will consider some partial ordering relations of life distribution under residual life functions and equilibrium distributions.

• Journal of the Korean Data and Information Science Society
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• 제21권5호
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• pp.967-972
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• 2010

We shall consider estimations of an exponetiated parameter of the exponentiated Pareto distribution with known scale and threshold parameters. A quotient distribution of two independent exponentiated Pareto random variables is obtained. We also derive the distribution of the ratio of two independent exponentiated Pareto random variables.

• Journal of the Korean Data and Information Science Society
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• 제18권2호
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• pp.573-584
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• 2007

We define a skew-symmetric Laplace distribution by a symmetric Laplace distribution and evaluate its coefficient of skewness. And we derive an approximate maximum likelihood estimator(AME) and a moment estimator(MME) of a skewed parameter in a skew-symmetric Laplace distribution, and hence compare simulated mean squared errors of those estimators. We compare asymptotic mean squared errors of two defined estimators of reliability in two independent skew-symmetric distributions.

• Journal of the Korean Data and Information Science Society
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• 제17권3호
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• pp.687-705
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• 2006

In this paper we consider GPH distribution that is defined as a distribution for sum of random number of random variables following exponential distribution. We establish approximation process of general distributions to GPH distributions and offer numerical results for various cases to show the accuracy of the approximation. We also propose analysis method of delay distribution of queueing systems using approximation to GPH distributions and offer numerical results for various queueing systems to show applicability of GPH approximation.

• Journal of the Korean Data and Information Science Society
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• 제18권4호
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• pp.1205-1214
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• 2007

We define a skew-symmetric double Rayleigh distribution by a symmetric double Rayleigh distribution, and derive an approximate maximum likelihood estimator(AML) and a moment estimator(MME) of a skewed parameter in a skew-symmetric double Rayleigh distribution, and hence compare simulated mean squared errors of those two estimators. We also compare simulated mean squared errors of two proposed estimators of reliability in two independent skew-symmetric double Rayleigh distributions.