• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.263-268
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• 2003

The Electrical insulation design and testing of high temperature superconducting (HTS) coil for high temperature superconducting fault current limiter (HTSFCL) has been performed. Electrical insulating factors of HTS coil for HTSFCL are turn-to-turn, layer-to-layer. The electrical insulation of turn-to-turn depends on surface length, and the electrical insulation of layer-to-layer depends on surface length and breakdown strength of L$N_2$. Therefore, two basic characteristics of breakdown and flashover voltage were experimentally investigated to design electrical insulation for 6.6㎸ Class HTSFCL. We used Weibull distribution to set electric field strength for insulation design. And mini-model HTS coil for HTSFCL was designed by using Weibull distribution and was manufactured to investigate breakdown characteristics. The mini-model HTS coil had passed in AC and Impulse withstand test.

• International Journal of Reliability and Applications
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• v.7 no.2
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• pp.89-99
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• 2006

A new classes of life distribution, namely harmonic used better than aged in expectation in upper tail (HUBAEUT) is introduced. Testing exponentiality against this class is investigated using kernel method. The limiting null and nonnull distribution of the test statistics is normal and the null variance is calculated exactly. Selected critical values are tabulated for sample sizes of 5(1)40. Power of the test are estimated by simulation. the efficacies of the test statistics used for testing against HUBAEUT are calculated for som common alternatives and are compared to some other procedures. It is shown that proposed test is simple, has high relative efficiency and power for some commonly used alternatives. The set of real data are used as an examples to elucidate the use of the proposed test statistics for practical reliability.

• Journal of the Korean Society of Visualization
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• v.17 no.2
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• pp.67-72
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• 2019

In this study, we investigate the non-reacting and reacting performance of single nozzle for post H class gas turbine by using commercial CFD tool, CONVERGE, based on adaptive mesh refinement. By varying swirl number and mixing length of base nozzle design. Through the numerical analysis, basic phenomena can be well described with respect to fuel concentration for non-reacting flow, temperature distribution, velocity vector and combustion outlet temperature distribution for reacting flow. However, there are rooms for improvements in model accuracy by comparing test results. Comparison between numerical analysis are planning for further study.

• Journal of KIISE:Software and Applications
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• v.32 no.8
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• pp.781-788
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• 2005

LDA (Linear Discriminant Analysis) is a data discrimination technique that seeks transformation to maximize the ratio of the between-class scatter and the within-class scatter While it has been successfully applied to several applications, it has two limitations, both concerning the underfitting problem. First, it fails to discriminate data with complex distributions since all data in each class are assumed to be distributed in the Gaussian manner; and second, it can lose class-wise information, since it produces only one transformation over the entire range of classes. We propose three extensions of LDA to overcome the above problems. The first extension overcomes the first problem by modeling the within-class scatter using a PCA mixture model that can represent more complex distribution. The second extension overcomes the second problem by taking different transformation for each class in order to provide class-wise features. The third extension combines these two modifications by representing each class in terms of the PCA mixture model and taking different transformation for each mixture component. It is shown that all our proposed extensions of LDA outperform LDA concerning classification errors for handwritten digit recognition and alphabet recognition.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2000.11b
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• pp.75-78
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• 2000

This study purpose that researching Side- TeoMaru of upper-class houses in traditional An-Chae space and researching regional characteristics. Side-TeoMaru type is An-Bang and Gunner-Bang. That is found Chungchong-Do, Cholla-Do, Kyongsangnam-Do. I found different distribution in this region. This study has researched by measurement and personal interview.

• Journal of the Korean Data and Information Science Society
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• v.17 no.2
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• pp.449-453
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• 2006

In teaching statistics in the secondary school, most math teachers do it and students enjoy it well before 11th grade. But, both of teachers and students feel statistics hard at 11th grade, which has been contained permutations, combinations, random variables, probability distributions, hypotheses and tests for normal distribution. In this study, we explore the efficient teaching methods of statistics for math teachers and also find many students enjoying it.

• Proceedings of the Korean Society of Computational and Applied Mathematics Conference
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• 2003.09a
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• pp.12.1-12
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• 2003

Sufficient conditions are given under which a generalized class of kernel-type estimators allows asymptotic approximation On the modulus of continuity This generalized class includes sample distribution function, kernel-type estimator of density function, and an estimator that may apply to the censored case. In addition, an application is given to asymptotic normality of recursive density estimators of density function at an unknown point.

• Bulletin of the Korean Mathematical Society
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• v.35 no.2
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• pp.227-234
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• 1998

Criteria are derived for the existence of a unique invariant oprobability distribution of a class of nonlinear pth-order autoregressive oprocesses, which reformulate those of Tweedie's. It will be shown that the criteria in this paper are easily applicable to the linear or piecewise linear case so that some of the earlier results are immediate consequences of our main results.

• Journal of applied mathematics & informatics
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• v.15 no.1_2
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• pp.147-158
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• 2004

Sufficient conditions are given under which a generalized class of kernel-type estimators allows asymptotic approximation on the modulus of continuity. This generalized class includes sample distribution function, kernel-type estimator of density function, and an estimator that may apply to the censored case. In addition, an application is given to asymptotic normality of recursive density estimators of density function at an unknown point.

• International Journal of Reliability and Applications
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• v.10 no.2
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• pp.81-88
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• 2009

A non-parametric procedure is presented for testing exponentially against used better than aged in convex ordering class (UBAC) of life distributions based on u-test. Convergence of the proposed statistic to the normal distribution is proved. Selected critical values are tabulated for sample sizes 5(5)40. The Pitman asymptotic relative efficiency of my proposed test to tests of other classes is studied. An example of 40 patients suffering from blood cancer disease demonstrates practical application of the proposed test.