• Journal of the Korean Data and Information Science Society
• /
• 제16권4호
• /
• pp.1107-1117
• /
• 2005

We consider the problem of estimating the scale and shape parameters in the Weibull distribution based on censored samples. We propose the approximate maximum likelihood estimators (AMLEs) of the scale and shape parameters in the Weibull distribution based on Type-II censored samples. We compare the proposed estimators in the sense of the mean squared error (MSE).

• Journal of the Korean Data and Information Science Society
• /
• 제16권4호
• /
• pp.923-931
• /
• 2005

The two parameter generalized exponential distribution was recently introduced by Gupta and Kundu (1999). It is observed that the generalized exponential distribution can be used quite effectively to analyze skewed data set. This paper develops the accelerated life test model using generalized exponential distribution and considers maximum likelihood estimation of parameters under the tampered random variable model. To show the performance of proposed maximum likelihood estimates, some simulation will be performed. Using a real data set, an example will be given.

• Journal of the Korean Data and Information Science Society
• /
• 제24권6호
• /
• pp.1449-1454
• /
• 2013

There are many methods for measuring the difference between two location parameters. In this paper, statistics are proposed in order to estimate the difference of two location parameters. The statistics are designed not using the means, variances, signs and ranks, but with the cumulative distribution functions. Hence these are measured as the differences in the area between two univariate cumulative distribution functions. It is found that the difference in the area between two empirical cumulative distribution functions is the difference of two sample means, and its integral is also the difference of two population means.

• 대한수학회보
• /
• 제53권5호
• /
• pp.1549-1566
• /
• 2016

Denote $M_n$ the maximum of n independent and identically distributed variables from the generalized short-tailed symmetric distribution. This paper shows the pointwise convergence rate of the distribution of $M_n$ to exp($\exp(-e^{-x})$) and the supremum-metric-based convergence rate as well.

• Journal of the Korean Data and Information Science Society
• /
• 제15권2호
• /
• pp.387-394
• /
• 2004

Zero-Inflated Poisson distribution is Poisson distribution with excess zeros. Recently defects of product hardley happen in the manufacturing process. In this case it is desirable to apply to the Zero-Inflated Poisson distribution rather than Poisson. Our target of this paper is to study the tests for changes of rate of defects after the unknown change-point. We are going to compare the powers of the two proposed tests with likelihood tests by the simulations.

• Journal of the Korean Data and Information Science Society
• /
• 제17권3호
• /
• pp.687-705
• /
• 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 applied mathematics & informatics
• /
• 제40권1_2호
• /
• pp.1-13
• /
• 2022

This article introduces a new distribution called length-biased powered inverse Rayleigh distribution. Some of its statistical properties are derived. Maximum likelihood procedure is applied to report the point and interval estimations of all model parameters. The proposed distribution is also applied to two real data sets for illustrative purposes.

• 유통과학연구
• /
• 제21권4호
• /
• pp.57-67
• /
• 2023

Purpose: This study aims to measuring the employee performance distributions of company in using relationship analysis between motivation, organization learning, compensation, and Organizational commitment. Research design and methodology: The study was conducted on 102 employees as a sample. Data were analyzed using Path Analysis in Structural Equation Modeling (SEM) with PLS. Results: the research result has shown that motivation and compensation have a positive significant effect on organizational commitment. While organizational learning has negative and insignificant effect on organizational commitment. Furthermore, motivation, organizational learning and motivation have no significant effect on employee performance distribution and organizational commitment has a positive significant effect on employee performance distribution. Results for mediating effect has obtained where organizational commitment mediates the effect of motivation and compensation on employee performance distribution, but cannot mediate the effect of organizational learning on employee performance distribution. Conclusion: Organizational commitment in this study can make employees feel comfortable and attached to the company so that employees can perform well to achieve company goals. Motivation and compensation are driving factors in improving employee performance distribution and will achieved if employees have good organizational commitment. In this study, organizational learning is not an important factor in improving employee performance distribution.

• 산경연구논집
• /
• 제3권1호
• /
• pp.25-29
• /
• 2012

The purpose of this study is to examine the development of the pharmaceutical distribution industry. The pharmaceutical industry is are expected to suffer a heavy blow when the Free Trade Agreement (FTA) is introduced, despite its best efforts. Therefore, adequate solutions must be found. Section II introduces the Korean pharmaceutical distribution system and its current situation; Section III explores the distribution system's strengths and weaknesses. Section IV, identifies the problem and possible solutions for the Korean pharmaceutical distribution system; Section V summarizes and concludes this paper and acknowledges its limitations. Finally, this paper has a clear limitation. The lack of objective information and scientific analysis due to the data being based on interviews with company representatives is its most significant shortcoming. However, it offers implications for new directions for future research.

• Journal of the Korean Data and Information Science Society
• /
• 제23권4호
• /
• pp.797-805
• /
• 2012

Many circular distributions are known to be not only asymmetric but also bimodal. Hidden truncation method of generating asymmetric distribution is applied to a bivariate circular distribution to generate an asymmetric circular distribution. While many other existing asymmetric circular distributions can only model an asymmetric data, this new circular model has great flexibility in terms of asymmetry and bi-modality. Some properties of the new model, such as the trigonometric moment generating function, and asymptotic inference about the truncation parameter are presented. Simulation and real data examples are provided at the end to demonstrate the utility of the novel distribution.