• Proceedings of the Korea Multimedia Society Conference
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• 2003.11b
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• pp.569-572
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• 2003

본 연구에서는 뉴우턴법에 기초한 고정점 알고리즘의 신경망 기반 독립성분분석에 kurtosis를 추가한 독립성분의 군집화를 제안하였다. 여기서 뉴우턴법의 고정점 알고리즘은 엔트로피에 기초한 목적 함수의 근을 구하는 근사화 방법으로 빠른 성분분석을 위함이고, kurtosis는 독립성분의 추출순서를 고려하지 않는 속성을 개선하기 위함이다. 제안된 기법을 256$\times$256 픽셀의 8개 혼합영상의 분리에 적용한 결과, 제안된 방법은 기존의 독립성분분석에서 분석순서를 고려치 않는 제약을 효과적으로 해결 할 수 있음을 확인하였다.

• Magazine of the Korea Concrete Institute
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• v.7 no.1
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• pp.89-96
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• 1995

본 연구는 시멘트 경화체 중의 Cl 고정화 메카니즘을 규명하는 연구의 일환으로 시멘트의 C3A 함유량에 따른 Cl 고정화 효과를 세공용액 분석방법에 의해 조사한 것으로 C3A함유량 0.46 9.65%의 4가지 시멘트와 C3A를 함유하지 않은 초속경 시멘트 페이스트를 밀봉용기내에서 양생시켜 재령 28일에 세공용액을 추출하여 세공용액 중의 Cl 과 OH 농도를 측정, C3A함유량이 Cl 고정화에 미치는 영향을 검토한 것이다. 연구결과 세공용액 중의 Cl 농도는 NaCl 혼입량에 관계없이 시멘트 중의 C3A량이 증가함에 따라 낮아져 시멘트 경화체 내에서 Cl 의 고정화에 C3A가 매우 효과적임을 알 수 있었다. 세공용액의 Cl /OH 는 Cl 혼입량이 시멘트 중량의 0.3%인 경우 강재부동태막을 파괴하는 0.3보다 낮았으며 X선회절분석에 의해 C3A에 의한 고정화 메카니즘은 프리델씨염(Friedel's salt)의 생성에 의함을 확인하였다.

• Journal of the Korean Data and Information Science Society
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• v.21 no.4
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• pp.651-667
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• 2010

In this paper, using a meta analysis of anti-hyperlipidemia effect of soybeans were studied. Studied the effects of soybeans using Hedges' standardized mean difference looked at the effect. Applying the fixed-effects model analysis of fecal cholesterol and total cholesterol and triglycerides showed a statistically significant reduction in HDL cholesterol increase was statistically significant at. In addition, the homogeneity of all variables by running the test did not meet the homogeneity of the kidney weight, between weight, HDL cholesterol, LDL cholesterol, total cholesterol, and triglycerides in the random effects model against the results of the analysis conducted by a statistically significant variable that did not.

• International Area Studies Review
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• v.22 no.2
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• pp.3-18
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• 2018

This paper analyzes both the FTA effects and FTA spillover effects on bilateral trade using 62 countries' panel data during the period of 2003 ~ 2013. To this end, we construct a FTA dummy variable for the effect of FTA in the model and the weighted FTA matrix interacted with export and import for the spillover effect of FTA. Gravity model is applied to the empirical analysis with GMM, fixed and random effects, and PPML estimation. As a result of the analysis, FTA variables have positive relationships with bilateral export and import. The weighted FTA matrix interacted with export and import also have positive signs on the bilateral export and import in all estimations. Thus, we conclude that various FTAs of neighbor or 3rd countries increase the bilateral export and import. We provide some implications that a country to increase the amount of trade has a trade relationship with the countries having various FTAs and for the FTA effect analysis, the three-country model is better than to the two-country model.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.2
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• pp.79-82
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• 2015

현재 IMT 용도의 주파수 포화로 인해, 새로운 주파수 대역을 확보 예정에 있다. 새로운 주파수 대역에서 새로운 서비스를 개시하기 위해서는 그 주파수 대역을 사용하고 있는 기존 시스템과의 공유연구가 필요하다. 본고에서는 5G의 후보 주파수 대역으로 주목을 받고 있는 밀리미터 대역에서 고정통신과의 간섭 효과를 분석하여 보여준다.

• The Journal of the Korea Contents Association
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• v.17 no.3
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• pp.199-211
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• 2017

The notable findings are as follow: First, men show higher level of perceiving open marriage, sex-role, acceptance of extra-marital relationship and intention of extra-marital sex than that of women. Second, the effects of men's perception of sex-role and open marriage, and the acceptance of extra-marital relationship have direct effects on their intention of extra-marital sex. The acceptance of extra-marital relationship shows the mediation effect on the path between that of open marriage and extra-marital sex among men. However, men's perception of sex-role does not affect the acceptance of extra-marital relationship. Lastly, women's perception of sex-role and open marriage, and the acceptance of extra-marital relationship directly influence the intention of extra-marital sex each, including the mediating effect of accepting extra-marital relationship between that of open marriage and extra-marital sex which are similar to the men's trend. Women's perception of sex-role show the direct effect on the acceptance of extra-marital relationship unlike man's trend. Therefore, the fact demonstrates that the effect of perceiving of sex-role on the intention of extra-marital sex is different according to gender. Some practical and political implications are discussed based on the study's findings.

• Journal of the Korean Data and Information Science Society
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• v.21 no.2
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• pp.231-240
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• 2010

If only fixed effects exist in a 4 $\times$ 4 balanced incomplete block design, powers of FR statistic for testing a main effect show the highest level with a few replications. Under the exponential and double exponential distributions, FR statistic shows relatively high powers with big differences as compared with the F statistic. Further in a traditional balanced incomplete block design, powers of FR statistic having a fixed main effect and a random block effect show superior preference for all situations without regard to the effect size of a main effect, the parameter size and the type of population distributions of a block effect. Powers of FR statistic increase in a high speed as replications increase. Overall power preference of FR statistic for testing a main effect is caused by unique characteristic of a balanced incomplete block design having one main and block effect with missing observations, which sensitively responds to small increase of main effect and sample size.

• Journal of Korea Water Resources Association
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• v.44 no.1
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• pp.1-8
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• 2011

This paper addresses the correlation between the flood damage cost and recovery cost. National data (15 regions) for 20 years, panel data, has been analyzed for this test. Model specification of panel data analysis depends on the characteristics of data set and "fixed" or "random" effects model can be used. The results are represented in both models. As we expected all independent variables show positive relationship with recovery cost, except for the number of death and suffers. The damage of public facilities, such as rivers and road are the major factors on the damage and recovery cost, which means that flood damage can not be decreased without decreasing damages of public facilities from floods. Especially, the recovery cost is always higher than the damage cost and investment for flood control. Unlikely, government investment for flood control is the highest and recovery cost is the always lower than da mage cost andinvestment in Japan. Which means that proper investment can reduce economic damage cost of flood and recovery cost.

• Journal of Korean Society of Forest Science
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• v.111 no.1
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• pp.136-149
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• 2022

In this study, the performance of a nonlinear mixed-effects (NLME) model used to estimate the stem taper of Pinus densiflora in Gangwon Province was compared with that of a nonlinear fixed-effects (NLFE) model using several performance measures. For the diameters of whole tree stems, the NLME model improved on the performance of the NLFE model by 26.4%, 42.9%, 43.1%, and 0.9% in terms of BIAS, MAB, RMSE, and FI, respectively. For the cross-section areas of whole tree stems, the NLME model improved on the performance of the NLFE model by 67.7%, 44.7%, 45.8%, and 1.0% in terms of BIAS, MAB, RMSE, and FI, respectively. Based on the analysis of 12 relative height classes of tree stems, stem taper estimation performance was also reasonably improved by the NLME model, which showed better MAB, RMSE, and FI at every relative height class compared with those of the NLFE model. In some classes, the NLFE model had better BIAS than the NLME model (stem diameter: 0.05, 0.2, 0.3, and 0.8; stem cross-section area: 0.05, 0.3, 0.5, 0.6, and 1.0). However, the NLME model enhanced the performance of stem diameter and cross-section area estimations at the lowest stem part (0.2 m from the ground). Improvements for stem diameter in terms of BIAS, MAB, RMSE, and FI were 84.2%, 69.8%, 68.7%, and 3.1%, respectively. For stem cross-section areas, the improvements in BIAS, MAB, RMSE, and FI were 98.5%, 70.1%, 68.7%, and 3.1%, respectively. The cross-section area at 0.2 m from the ground occupied 22.7% of total cross-section area. Improvements in estimation of cross-section area at the lowest stem part indicate that stem volume estimation performance could also be enhanced. Although NLME models are more difficult to fit than NLFE models, the use of NLME models as a standard method for the estimating the parameters of stem taper equations should be considered.

• Journal of Labour Economics
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• v.27 no.1
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• pp.1-25
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• 2004

In knowledge-based economy where the human capital has an strong compatibilities, the life cycle of technologies and skills get shorter, and the mobility of labor get greater, the role of the signal system of qualifications have greater importance. This article used the KLIPS(Korean Labor Institute Panel Study) data, and analysed the factors of the acquisition of qualifications and the employment and wage effects of the acquisition of qualifications by fixed effects logit model and random effects model. The lower school stratification acquired the more qualifications, and in the case of men the unemployed one acquired the more qualifications. The employment effects of the acquisition of qualifications are significant at first year and second year in women, but the men's of the employment effects of acquisition of qualifications are not significant. The wage effects of the acquisition of qualifications are not significant. The results of the regression suggest that in Korea the signal system of qualifications do not working, and that the qualifications in Korea need to reform.