• The Korean Journal of Applied Statistics
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• v.10 no.1
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• pp.105-119
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• 1997

Barnwal and Paul(1988) derived the likelihood ratio statistic and $C(\alpha)$ statistic for testing the equality of the means of several groups of count data in the presence of a common dispersion parameter. These tests are generalized to be applicable without the restriction of a common dispersion parameter. And the assumed model of data is also extended from negative binomial to double exponential Poisson model. Monte Carlo simulations show the superiority of $C(\alpha)$ statistic based on the double exponential Poisson family which has a very simple form and requires estimates of the parameters only under the null hypothesis.

• The Korean Journal of Applied Statistics
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• v.24 no.6
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• pp.1197-1211
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• 2011

The actual power performance of historical structural change tests are compared under various alternatives. The tests of interest are F, CUSUM, MOSUM, Moving Estimates and empirical distribution function tests with both recursive and ordinary least-squares residuals. Our comparison of the structural tests involves limiting distributions under the hypothesis, the ability to detect the alternative hypotheses under one or double structural change, and smooth change in parameters. Even though no version is uniformly superior to the other, the knowledge about the properties of those tests and connections between these tests can be used in practical structural change tests and in further research on other change tests.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.2
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• pp.53-68
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• 1999

This paper presents a nonparametric method to test if the mean difference of DEA efficiency estimates between two groups statistically exists. A proposed method employs a bootstrapping approach to generation BCC efficiency estimates through Monte Carlo simulation resampling process. For the purpose of demonstration, we empirically apply the proposed method to the korean bank industry and compare its result with the result by the traditional deterministic DEA method. The nonparametric statistical hypothesis testing procedure in this study, which considers not only stochastic variability of the DEA data, but also random radial deviations off the efficient frontier, serves as a useful tool for dbjectively evaluating whether the mean difference of DEA efficiency estimates between groups is statistically significant.

• Journal of Preventive Medicine and Public Health
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• v.28 no.2 s.50
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• pp.450-461
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• 1995

This paper tested by using Micro TSP, an empirical econometric analysis to approve officially a hypothesis of price elasticity of the demand for medical care services in Korean national medical insurance and the economic effect of health care delivery system with time-series datas of Medical Insurance Statistical Yearbook$(1981\sim1993)$. The results suggest that the Korean medical insurance system shows moral hazard due to the change of coinsurance and the economic effect according to intervention of the health care delivery system, but it is different by insurers regardless of the same structure of the medical insurance scheme.

• Journal of Information Technology Services
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• v.12 no.3
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• pp.95-109
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• 2013

This paper discussed about creativity and knowledge management variables as for effect factors on the management performance of IT service firms. Specially the mediation effects of knowledge management variables between the creativity and management performance were examined. To prove empirically the related hypothesis, the statistical analysis were based on the response from the 160 Korean IT Service firms. As an analysis results, it was found that the creativity of organizations was not the direct effector on the management performance. But the virtue of knowledge which are accumulated from knowledge management activity and shared in organizations was the direct effector. Also, the knowledge management activity is mediator on the in the relationship between the creativity and management performance. So this paper suggests that knowledge management activity and knowledge's virtue in the related the creativity in organizations are the important mediate factors for enhancement of IT service firm's performance.

• Journal of the Korea Computer Industry Society
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• v.2 no.3
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• pp.309-320
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• 2001

According to the increasing of the cars, road traffic confused. If we estimate the traffic confusion use of statistical research, road traffic improved considerably. This paper analysis element that affected a expressway speed and investigate the mutual relation. For the accomplish it, we construct the DB for traffic of a expressway and applied a hypothesis to road traffic DB, we obtain the results from a various method with Data Mining operation.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.4
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• pp.296-303
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• 2007

This paper proposes a new width control system composed of an ANWC(Automatic Neural network based Width Control) and a fuzzy-PID controller in hot strip finishing mills which aims at obtaining the desirable width. The ANWC is designed using a neural network based width prediction model to minimize a width variation between the measured width and its target value. Input variables for the neural network model are chosen by using the hypothesis testing. The fuzzy-PlD control system is also designed to obtain the fast looper response and the high width control precision in the finishing mill. It is shown through the field test of the Pohang no. 1 hot strip mill of POSCO that the performance of the width margin is considerably improved by the proposed control schemes.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.75-76
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• 2008

A low complexity encoding scheme for coarse grain scalability is proposed. The proposed method exploits the statistics of residuals between current and reference blocks using the macroblock mode predicted from the previous quality layer. To test how the mode is optimal in the current layer, the statistical hypothesis testing for the variances of the residual sub-blocks is performed. The proposed method reduces the total encoding time up to 51% when three CGS scalability layers are encoded. However, the quality degradation and bit-rate increment of the each layer are negligible.

• Journal of Korean Society for Quality Management
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• v.34 no.3
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• pp.66-72
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• 2006

The process capability indices are widely used to measure the capability of the process to manufacture items within the specified tolerance. Most evaluations on process capability indices focus on point estimates, which may result in unreliable assessments of process performance. The index $C_p$ has been widely used in various industries to assess process performance. In this paper, we propose new testing procedure on assessing $C_p$ index for practitioners to use in determining whether a given process is capable. The provided approach is easy to use and the decision making is more reliable. Whether a process is clearly normal or nonnormal, our bootstrap testing procedure could be applied effectively without the complexity of calculation. A numerical result based on the proposed approach is illustrated.

• Proceedings of the Korean Society for Quality Management Conference
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• 2010.04a
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• pp.183-190
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• 2010

The study is to examine the causal correlation between communication skill of organization and their job performance. In our model, we used these variables-innovation awareness, job satisfaction, organizational commitment as a parameter. In order to verify the hypothesis based on research model, a survey among researchers(sample size=117) who work in food company was carried out. Analyzing hypothesized model and following the statistical procedure, we could assure that these exist positive correlation with communication skill, innovation awareness, job satisfaction, organizational commitment and organization performance. A coefficient of coffelation between those variables was clearly high in the group with good communication skill. Among the parameters, the variable of innovation awareness was more effected on their job performance.