• 한국의학물리학회지:의학물리
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• 제17권4호
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• pp.232-237
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• 2006

본 연구의 목적은 Ir-192 선원의 검교정을 겉보기 방사능(apparent activity)을 이용하지 않고 물속 기준점에서 흡수선량을 측정함으로써 공기커마 세기(air-kerma strength, Sk)를 계산하고자 알고리즘을 개발하였다. 연구를 위하여 근접치료용 다목적 팬톰(multi purpose brachytherapy Phantom, MPBP)을 제작하였다. 물 흡수선량 측정은 고선량률 근접치료기(micro-Selectron, Nucletron, Netherlands)에 장착된 Ir-192 선원(Mallinckrodt Medical B.V., Netherlands)을 대상으로 측정하였다. 물 흡수선량은 몬테칼로 계산방법으로 계산된 이온전리함(TM30013, PTW, Germany)의 물 흡수선량 교정인자($N_{D.W.Q}$)를 이용하여 결정하였다. 물 흡수선량은 한 개의 선원에 대하여 4 cm에서 7 cm까지 측정하였다. 측정된 값은 전산화 치료계획 장치에서(plato BPS, ver 13.2, Nucletron, Netherlands) 계산된 값과 비교하였다. 공기커마 세기(Sk)는 기준점 5 cm되는 곳에서 3개의 Ir 선원에 대하여 구하였다. 계산된 공기커마 세기는 선원제조사에서 제공된 값과 비교하였다. 몬테칼로 계산방법으로 계산된 이온전리함의 물 흡수선량 교정인자는 5.28 cGy/nC이었다. 한 개 선원에서 측정한 물 흡수선량 값은 -2.16%에서 -0.84%까지 상대오차를 나타내었다. 공기커마 세기는 제조사에서 제공된 값과 비교하여 -0.6%에서 +1.8% 제조사 권고치 ${\pm}5%$ 이내로 잘 일치하였다. 본 연구에서 개발한 알고리즘은 기준점에서의 물 흡수선량을 정확히 결정함으로써 선원의 공기커마 세기를 구할 수 있었다. 이러한 물 흡수선량을 통한 Ir-192 선원의 검교정 방법들은 미국의학물리학회(AAPM) 보고서 TG-43에서 권고한 흡수선량 계산 알고리즘에 바로 적용할 수 있는 것으로 사료된다.

• 아동학회지
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• 제29권4호
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• pp.249-268
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• 2008

The Korean version of the Multidimensional Students' Life Satisfaction Scale for children(K-MSLSS) assesses children's subjective perceptions of Life Satisfaction(LS) in five conceptually relevant domains : Friends, School, Family, Living Environment, and Self. The purpose of the present study was to validate the five-factor structure of the K-MSLSS using Confirmatory Factor Analysis(CFA) procedures by means of the AMOS 7.0 statistical program. Of the 681 children(10.5 years, SD=1.1) recruited from three public elementary schools in Seoul 431 children were the calibration sample and 430 children were the validation sample. Results of the analyses found that the five-factor structure of K-MSLSS is applicable for use with Korean children from 9-12 years of age regardless of gender.

• Design & Manufacturing
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• 제8권2호
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• pp.30-36
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• 2014

In this study, surface deformation patterns have been investigated by the rigid-plastic finite element method for friction factor test in solid cylinder compression process. AA1100 and AA6063 aluminum alloys, which show different work hardening characteristics respectively, have been adopted as model materials used for analysis. The main objective of this study is to provide the deformation mechanics in detail in solid cylinder compression process, especially at the die/workpiece interface that is closely related with the frictional conditions. For this reason, solid cylinder compression process has been numerically analyzed. The surface flow patterns at the contact boundary have been analyzed in terms of surface expansion, surface expansion velocity, pressure distributions exerted on the die surface along the die surface. By defining bulge factor, barreling phenomenon also have been examined with calibration curves to verify their effects on the surface flow pattern that is important for evaluating the frictional condition at the interface.

• Journal of the Korean Data and Information Science Society
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• 제22권5호
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• pp.1007-1016
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• 2011

This article deals with the problem of testing for the correlation coefficient in the bivariate normal distribution. We propose Bayesian hypothesis testing procedures for the bivariate normal correlation coefficient under the noninformative prior. The noninformative priors are usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the default Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. A simulation study and an example are provided.

• Journal of the Korean Data and Information Science Society
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• 제25권4호
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• pp.961-970
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• 2014

This article deals with the problem of testing the equality of the scale parameters of several inverted exponential distributions. We propose Bayesian hypothesis testing procedures for the equality of the scale parameters under the noninformative prior. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the default Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. Simulation study and an example are provided.

• Journal of the Korean Data and Information Science Society
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• 제26권3호
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• pp.739-748
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• 2015

This paper deals with the problem of testing about the equality of the scale parameters in several inverse Gaussian distributions. We propose default Bayesian testing procedures for the equality of the shape parameters under the reference priors. The reference prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. Therefore we propose the default Bayesian testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. Simulation study and an example are provided.

• Journal of the Korean Data and Information Science Society
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• 제25권2호
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• pp.465-472
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• 2014

This article deals with the problem of testing the equality of the scale parameters in the half logistic distributions. We propose Bayesian hypothesis testing procedures for the equality of the scale parameters under the noninformative priors. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be dened up to a multiplicative constant. Thus we propose the default Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. Simulation study and an example are provided.

• Journal of the Korean Data and Information Science Society
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• 제24권4호
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• pp.949-957
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• 2013

In this paper, we consider the problem of testing the equality of the scale parameters in two parameter exponential distributions. We propose Bayesian testing procedures for the equality of the scale parameters under the noninformative priors. The noninformative prior is usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. Thus, we propose the default Bayesian testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. Simulation study and an example are provided.

• Journal of the Korean Data and Information Science Society
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• 제23권3호
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• pp.605-616
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• 2012

This article deals with the problem of testing on the common mean of several normal populations. We propose Bayesian hypothesis testing procedures for the common normal mean under the noninformative prior. The noninformative prior is usually improper and yields a calibration problem that makes the Bayes factor to be defined u to a multiplicative constant. So we propose the default Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. Simulation study and an example are provided.

• 한국전자통신학회논문지
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• 제15권3호
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• pp.405-412
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• 2020

서미스터 마운트는 전력의 변화에 따른 교정인자 값이 일정하여 정밀한 무선주파수 전력 측정에 사용하고 있다. 표준 마운트의 교정인자는 직류 대체법을 이용하여 전달표준과 직접 비교를 통해 10 MHz부터 1 GHz 대역까지 불확도 0.5 % 이하로 측정할 수 있다. 최근 직류 대체법 기반 정밀한 전력계의 산업계 보급으로 보다 간단하고, 빠른 측정이 가능함에 따라 동일한 불확도 수준의 단순 직접 비교 측정시스템을 설계하고, 부정합 오차의 분석을 통해 구성품의 최소 요구 사양을 제시하였다. 시스템 유효성 검증을 위해 시스템 불확도를 평가하였으며, 불확도 결과는 측정 주파수 대역에서 0.5 % 이내에서 잘 유지되었음을 보여준다.