• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.9
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• pp.816-820
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• 2007

We measured the electron drift velocity, W, in 0.5% $SF_6-Ar$ mixture over the E/N range from 30 Td to 300 Td and gas pressure range from 0.1 to 0.5 Torr by the double shutter drift tube with a variable drift distance, and calculated over the same E/N and gas pressure range by using the two-term approximation of the Boltzmann equation. The measured and calculated values at different gas pressure at each E/N was appreciable dependence in the results on the gas pressure.

• Communications for Statistical Applications and Methods
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• v.24 no.5
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• pp.481-492
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• 2017

This paper investigates a convergence rate of a test statistics given by two scale sampling method based on $A\ddot{i}t$-Sahalia and Jacod (Annals of Statistics, 37, 184-222, 2009). This statistics tests for longitudinal data having the existence of long memory dependence driven by fractional Brownian motion with Hurst parameter $H{\in}(1/2,\;1)$. We obtain an upper bound in the Kolmogorov distance for normal approximation of this test statistic. As a main tool for our works, the recent results in Nourdin and Peccati (Probability Theory and Related Fields, 145, 75-118, 2009; Annals of Probability, 37, 2231-2261, 2009) will be used. These results are obtained by employing techniques based on the combination between Malliavin calculus and Stein's method for normal approximation.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.248-251
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• 2002

We measured the electron drift velocity, W, in 0.5% $SF_{6}$-Ar mixture over the E/N range from 30 Td to 300 Td and gas pressure range from 0.1 to 8 Torr by the double shutter drift tube with a variable drift distance. This coefficient in the mixture was calculated over the same E/N and gas pressure range by using the two-term approximation of the Boltzmann equation. And the measured and calculated values at different gas number density at each E/N was appreciable dependence in the results on the gas number density,

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.4
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• pp.115-122
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• 1994

Roberige had proposed a method of linear approximation using strips. This method is known to be fast relatively, and the distance between the given curve and calculated straight line is not greater than an allowable error. But this method generates many break points. Later, Leng and Yang proposed the dynamic strip algorithm with the rotation of strips which reduced the number of greak points at the sacrifice of the speed. The method using the seperate rotation of two strip lines proposed in this paper is faster than Leng and Yang's but generates almost the same number of break points as Leng and Yang's.

• Communications for Statistical Applications and Methods
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• v.25 no.4
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• pp.355-371
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• 2018

The two parameter negative exponential distribution has many practical applications in queuing theory such as the service times of agents in system, the time it takes before your next telephone call, the time until a radioactive practical decays, the distance between mutations on a DNA strand, and the extreme values of annual snowfall or rainfall; consequently, has many applications in reliability systems. This paper considers an estimation problem of stress-strength model with two parameter negative parameter exponential distribution. We introduce a maximum penalized likelihood method, Bayes estimator using Lindley approximation to estimate stress-strength model and compare the proposed estimators with regular maximum likelihood estimator for complete data. We also introduce a maximum penalized likelihood method, Bayes estimator using a Markov chain Mote Carlo technique for incomplete data. A Monte Carlo simulation study is performed to compare stress-strength model estimates. Real data is used as a practical application of the proposed model.

• Proceedings of the Korean Information Science Society Conference
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• 1999.10b
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• pp.647-649
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• 1999

본 논문은 매쉬 분할시 생성되는 정점들과 그 점들의 극한위치와의 차이로 정의되는 근접거리 메트릭을 이용한 적응적 Loop 메쉬분할법을 제안한다. 근접거리 메트릭은 모든 approximation 분할법에 적용가능하며, 이 메트릭을 이용하여 초기메쉬를 사용자 입력 허용치에 따라 적응적으로 분할하여 적은 데이터로 극한메쉬에 근접한 결과를 생성할 수 있다. 또한, 본 논문에서 제시한 적응적 Loop 분할법은 다단계 메쉬표현이나 메쉬 편집 등 Loop 메쉬분할법이 사용되는 알고리즘에 유용하게 적용시킬 수 있다.

• Journal of the Korean Operations Research and Management Science Society
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• v.13 no.2
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• pp.25-33
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• 1988

An efficient heuristic solution procedure is developed for the minimum location problems. The gradient direction method and modified gradient approach are developed due to the differentiability of the objective functions. Suboptimal step size is obtained analytically. A Modified Gradient Procedure (NGP) is presented and compared with the hyperboloid approximation procedure (HAP) which is one of the best known methods.

• Journal of the Korean Society of Safety
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• v.5 no.3
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• pp.44-50
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• 1990

This study is conducted to examine the theoretical background of characteristics for electric shock encountered in special high-voltage electric lines among the accidents of electric shock, and to calculate applied current to human body and field strength over the head by means of numerical anaysis through FEM(Finite Element Method), and to make clear the hazard level to the human body, and to establish the approach limit distance of human body to the electric lines, which could be applied to the safety standard while working in the vicinity of special high-voltage electric lines.

• Journal of the Korean Data and Information Science Society
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• v.17 no.2
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• pp.543-557
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• 2006

This paper is concerned with the applicability of the chi-square approximation to the six disparity statistics: the Pearson chi-square, the generalized likelihood ratio, the power divergence, the blended weight chi-square, the blended weight Hellinger distance, and the negative exponential disparity statistic. Three dimensional contingency tables of small and moderate sample sizes are generated to be fitted to all possible hierarchical log-linear models: the completely independent model, the conditionally independent model, the partial association models, and the model with one variable independent of the other two. For models with direct solutions of expected cell counts, point estimates and confidence intervals of the 90 and 95 percentage points of six statistics are explored. For model without direct solutions, the empirical significant levels and the empirical powers of six statistics to test the significance of the three factor interaction are computed and compared.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.267-272
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• 1993

This paper presents the performance and problems in analysis method and testing system of Electronic Speckle Pattern Interferometry (ESPI) method, in measuring two-dimensional in-plane displacement. The anyalysis result of measurement by ESPI is quite comparable to that of measurement by strain gauge method. This implieds that the method of ESPI is a very effective tool in non-contact two-dimensional in-planc strain analysis. But there is a controversal point,measurment error. This error is discussed to be affected not by ESPI method itseif, but by its analysis scheme of the interference fringe,where the first-order interpolation has been applied to the points of strain measured. In this case, it is turned out that the more errors would be occured in the large interval of fringe. so, this paper describes a computer method for drawing when the height is available only for some arbitary collection of points, the method is based on a distance-weighted, least-squares approximation technique, with the weight varying with the distance of the data points.