• Communications for Statistical Applications and Methods
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• 제21권4호
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• pp.297-307
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• 2014

We derive a test statistic for the general linear test in the ridge regression model. The exact distribution for the test statistic is too difficult to derive; therefore, we suggest an approximate reference distribution. We use numerical studies to verify that the suggested distribution for the test statistic is appropriate. A asymptotic result for the test statistic also is considered.

• Journal of the Korean Statistical Society
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• 제35권3호
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• pp.331-341
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• 2006

An approximate distribution of the plug-in estimator of the squared coefficient of variation ($CV^2$) is derived by using Edgeworth expansions under general population models. Also bias of the estimator is investigated for several important distributions. Under the normal distribution, we proposed the new estimator for $CV^2$ based on median of the sampling distribution of plug-in estimator.

• Journal of the Korean Statistical Society
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• 제25권3호
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• pp.393-406
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• 1996

We obtain the general moment of non-central Wishart distribu-tion, using the J-th moment of a matrix quadratic form and the 2J-th moment of the matrix normal distribution. As an example, the second moment and kurtosis of non-central Wishart distribution are also investigated.

• Communications for Statistical Applications and Methods
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• 제13권1호
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• pp.89-99
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• 2006

This article deals with the problem of estimating parameters of Burr Type XII distribution, on the basis of a general progressive Type II censored sample using Bayesian viewpoints. The maximum likelihood estimator does not admit closed form but explicit sharp lower and upper bounds are provided. Assuming squared error loss and linex loss functions, Bayes estimators of the parameter k, the reliability function, and the failure rate function are obtained in closed form. Finally, a simulation study is also included.

• 산경연구논집
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• 제8권1호
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• pp.15-22
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• 2017

Purpose - Retail companies are turning from one type of retailer to multiple business categories through various reasons, such as taking advantage of existed types of retailers' channel distribution, information and know-how, and entering into new types of retailers. However, there is few research conducted about multiple type of retailers. Research design, data, and methodology - In this research, the references, data and new stores on E-mart will be collected. The dissertation, annual report, statistical data, land-book of E-mart will be also collected to confirm whether E-mart has made any acquisition towards another company. Results - There is a tendency to new stores expansion, store enlargement and prolonging the opening preparation of new stores, based on the core of new stores expansion of E-mart as a general supermarket type of retailers. Based on general supermarket type of retailers, E-mart begins to diversify its retail company's type of retailers. Conclusions - As a general supermarket which is the most important type of retailers, E-mart is expanding into SSM type of retailers to seek new power of growth while slowdown growth is shown in general supermarket type of retailers. The expansion into SSM type of retailers would be a wise option as a retail company, E-mart is able to keep growing in the future.

• 충청수학회지
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• 제25권3호
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• pp.501-505
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• 2012

In this paper, general classes of continuous distributions are characterized by considering the conditional expectations of functions of upper record statistics. The specific distribution considered as a particular case of the general class of distribution are Exponential, Exponential Power(EP), Inverse Weibull, Beta Gumbel, Modified Weibull(MW), Weibull, Pareto, Power, Singh-Maddala, Gumbel, Rayleigh, Gompertz, Extream value 1, Beta of the first kind, Beta of the second kind and Lomax.

• Journal of the Korean Data and Information Science Society
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• 제8권2호
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• pp.239-245
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• 1997

By assuming a general progressive Type-II censored sample, we propose the minimum risk estimator (MRE) and the approximate maximum likelihood estimator (AMLE) of the scale parameter of the one-parameter exponential distribution. An example is given to illustrate the methods of estimation discussed in this paper.

• Communications for Statistical Applications and Methods
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• 제20권6호
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• pp.427-438
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• 2013

Based on progressive Type II censored sampling which is an important method to obtain failure data in a lifetime study, we suggest a very general form of Bayesian prediction bounds from two parameters exponentiated Weibull distribution using the proper general prior density. For this, Markov chain Monte Carlo approach is considered and we also provide a simulation study.

• 유통과학연구
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• 제16권6호
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• pp.77-84
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• 2018

Purpose - The aim of this study was to analyze the educational needs of distribution company salespeople in core competencies for convergence and their general perception of convergence education. Furthermore, this study provides basic data on core competencies for convergence needed by them. Research design, data, and methodology - A survey was conducted on 104 distribution company salespeople who worked near Seoul, Korea to analyze the perceptions of their educational needs in core competencies for convergence education, according to their socio-demographic characteristics. The socio-demographic characteristics were gender, age, workplace size, education background, work experience and business category. The questionnaire consisted of demographic factors (7 questions), general perception of convergence education (5 questions), perception of importance of core competency for distribution company salespeople (9 questions), and current perception of distribution company salespeople on core competency of convergence workers (9 questions). Park et al.(2014)'s categorization of convergence core competencies was used: Cognitive convergence (creative thinking, critical thinking and understanding of convergence knowledge), convergence performance (problem solving, communications, collaboration and application of convergence tools) and attitude toward convergence (empathy and responsibility). Data was collected through an independent sample of t-tests and a one-way analysis of variance and the Borich Needs Assessment Model was used to identify the educational needs of distribution company salespeople in the core competencies of convergence education. Results- The results show that the subjects recognized the need for convergence education to be high among the general perceptions. The perception scores for workers of different backgrounds only varied according to the size of the business. Moreover, the results of the educational needs analysis and the ranks of the required core competencies of convergence workers by the subjects were as follows: 1. convergence knowledge understanding competency, 2. creative thinking competency, 3. convergence tool application competency, 3. communications competency, 4. problem solving competency, 5. collaboration competency, 6. critical thinking competency, 7. empathy competency, 8. responsibility competency. Conclusions - This study highlights the necessity of developing university curriculum that can nurture the core competencies of conversion education reflecting distribution company salespeople's requests as well as cultivating qualified convergence workers required by distribution company workers.

• 한국유기농업학회지
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• 제22권1호
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• pp.25-46
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• 2014

Since organized living cooperative associations sold their environment-friendly agricultural products directly to independent consumers in the past, the general distribution channels such as wholesalers had difficulty in handling these products. However, the ratio of distribution via wholesale channel has been gradually increased as consumption of environment-friendly agricultural products has expanded. This study is to address vitalization of wholesale distribution for environment-friendly agricultural products by gathering previous statistical data and analysis. In addition, statistical analysis are conducted by utilizing surveys on forwarders, consumers for environment-friendly agricultural products. As a result, the products producers ship are distributed through dealers at producers sites, producers cooperatives, or food process companies, food companies, internet shopping malls, large-scale distribution companies, consumer groups such as living cooperative associations, direct outlets at consumers sites, or exports. Among the channels, the large-scale distribution companies and franchised special shops account for 47%, the general supermarkets 15.7%, and living cooperative associations 14.6% respectively. By utilizing the research results on producers and consumers, and the distribution weight by channels for environment-friendly agricultural products, the distribution channels for living cooperative associations, wholesale markets, and large scale distribution companies are compared and evaluated. As a result, the level of producers' and consumers' satisfaction for them is the lowest since the low selling price for producers and high distribution margins.