• Proceedings of the Korean Statistical Society Conference
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• 2000.11a
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• pp.261-266
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• 2000

이변량 반복측정자료에서 Chinchilli 등(1996)이 제안한 가중일치상관계수는 두 변수의 일치성을 나타내는 측도이다. 기존에 제안된 가중일치상관계수 추정법은 변동효과 및 측정오차의 분산성분을 각각 최소제곱법으로 비편향 추정하여 구하는 것이다. 본 연구에서는 반복측정자료의 주변 우도함수를 설정한 후, 우도함수에 기초한 분산성분을 구하여 가중일치상관계수를 추정하는 방법을 제안한다. 이때, 각 분산성분은 유사/의사 우도함수 및 사후 분포에서 반복시행을 통하여 구해진다.

• The Korean Journal of Applied Statistics
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• v.21 no.4
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• pp.621-630
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• 2008

This paper discusses how to construct a generalized marginal logit model for analyzing repeated polytomous response data when some factors are applied to larger experimental units as treatments and time to a smaller experimental unit as a repeated measures factor. So, two different experimental sizes are considered. Weighted least squares(WLS) methods are used for estimating fixed effects in the suggested model.

• Journal of Digital Contents Society
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• v.18 no.1
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• pp.175-182
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• 2017

Noises are usually generated by various external causes and low quality devices in image data acquisition and recording as well as by channel interference in image transmission. Since these noise signals result in the loss of information, subsequent image processing is subject to the corruption of the original image. In general, image processing is performed in the mixed noise environment where common types of noise, known to be Gaussian and impulse, are present. This study proposes an iterative weighted mean filter for reducing mixed type of noise. Impulse noise pixels are first turned off in the input image, then $3{\times}3$ sliding window regions are processed by replacing center pixel with the result of weighted mean mask operation. This filtering processes are iterated until all the impulse noise pixels are replaced. Applied to images corrupted by Gaussian noise with ${\sigma}=10$ and different levels of impulse noise, the proposed filtering method improved the PSNR by up to 12.98 dB, 1.97 dB, 1.97 dB respectively, compared to SAWF, AWMF, MMF when impulse noise desities are less than 60%.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.41-48
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• 2022

This paper presents the unified Bayesian Tikhonov regularization method as a solution to total variation regularization. The integrated method presents a formula for obtaining the regularization parameter by transforming the total variation term into a weighted Tikhonov regularization term. It repeats until the reconstructed image converges to obtain a regularization parameter and a new weighting factor based on it. The experimental results show the effectiveness of the proposed method for the image restoration problem.

• The Korean Journal of Applied Statistics
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• v.21 no.1
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• pp.1-17
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• 2008

The ordinary least squares regression method of Haseman and Elston(1972) is most widely used in genetic linkage studies for continuous traits of sib pairs. Kruglyak and Lander(1995) suggested a statistic which appears to be a nonparametric counterpart to the Haseman and Elston(1972)'s regression method, but in fact these two methods are quite different. In this paper the relationships between these two methods are described and will be compared by simulation studies. One of the characteristics of the sib-pair linkage study is that the explanatory variable has only three different values and thus dependent variable is heavily replicated in each value of the explanatory variable. We propose a weighted least squares regression method which is more appropriate to this situation and the efficiency of the weighted regression in genetic linkage study was explored with normal and non-normal simulated continuous traits data. Simulation studies demonstrated that the weighted regression is more powerful than other tests.

• The Safety technology
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• no.204
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• pp.10-14
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• 2014

• Geophysics and Geophysical Exploration
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• v.8 no.2
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• pp.163-169
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• 2005

Recently, the velocity stack domain is having an attention as a very useful domain for various processing in seismic data processing. In order to be used in many applications, the velocity stack should be obtained through an inversion method and the used inversion should have properties like the robustness to noise and the parsimony of velocity stack result. Iteratively Reweighted Least-Squares (IRLS) method is the one of the inversion methods that have such properties. This paper describes the theoretical background, implementation of the method, and examines the characteristics and limits of the IRLS method.

• The Korean Journal of Applied Statistics
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• v.16 no.1
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• pp.55-69
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• 2003

In this article, we propose the weighted LAD (least absolute deviations) estimators for multi-dimensional contingency tables and drive an estimation method to estimate the proposed estimators. To illustrate the robustness of the estimators, simulation results are presented for several models Including log-linear models and models for ordinal variables in multidimensional contingency tables. Examples were also introduced.

• The Korean Journal of Applied Statistics
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• v.21 no.2
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• pp.291-299
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• 2008

This paper discusses model building for repeated binary response data with different time-dependent covariates each occasion. Since repeated measurements data are having correlated structure, weighed least squares(WLS) methodology is applied. Repeated measures designs are usually having different sizes of experimental units like split-plot designs. However repeated measures designs differ from split-plot designs in that the levels of one or more factors cannot be randomly assigned to one or more of the sizes of experimental units in the experiment. In this case, the levels of time cannot be assigned at random to the time intervals. Because of this nonrandom assignment, the errors corresponding to the respective experimental units may have a covariance matrix. So, the estimates of effects included in a suggested logit model are obtained by using covariance structures.

• Journal of KSNVE
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• v.8 no.1
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• pp.36-40
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• 1998

공항주변지역의 항공기 소음영향은 항공기 1대에 의한 소음크기나 시끄러움보다는 항공기가 계속하여 반복 운항하는데 더욱 큰 영향이 있다.그래서 ICAO가 1971년에 공포한 Annex 16 Aircraft Noise중에서 다수의 항공기에 의해 장기간 연속폭로 된 소음척도로서 EPNL에 항공기 운항회수와 운항시간대등을 고려한 WECPNL(가중 등가속 감각 소음 레벨 : Weighted Equivalent Continuous Perceived Noise Level)이 제안되었다.