• 한국재료학회지
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• 제22권4호
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• pp.190-194
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• 2012

The formation of high-quality polycrystalline silicon (poly-Si) on relatively low cost substrate has been an important issue in the development of thin film solar cells. Poly-Si seed layers were fabricated by an inverse aluminum-induced crystallization (I-AIC) process and the properties of the resulting layer were characterized. The I-AIC process has an advantage of being able to continue the epitaxial growth without an Al layer removing process. An amorphous Si precursor layer was deposited on Corning glass substrates by RF magnetron sputtering system with Ar plasma. Then, Al thin film was deposited by thermal evaporation. An $SiO_2$ diffusion barrier layer was formed between Si and Al layers to control the surface orientation of seed layer. The crystallinity of the poly-Si seed layer was analyzed by Raman spectroscopy and x-ray diffraction (XRD). The grain size and orientation of the poly-Si seed layer were determined by electron back scattering diffraction (EBSD) method. The prepared poly-Si seed layer showed high volume fraction of crystalline Si and <100> orientation. The diffusion barrier layer and processing temperature significantly affected the grain size and orientation of the poly Si seed layer. The shorter oxidation time and lower processing temperature led to a better orientation of the poly-Si seed layer. This study presents the formation mechanism of a poly seed layer by inverse aluminum-induced crystallization.

• Journal of Animal Science and Technology
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• 제46권6호
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• pp.903-908
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• 2004

다양한 포유동물의 미토콘드리아 유전자들에서 선택적 개시코돈(AIC)들이 보고되었다. 본 연구는 돼지 5 품종에서 mtDNA ND2 유전자의 AIC 양상을 분석하였다. 두 종류의 AIC 서열들이 발견되었고, 품종 집단간에서 각기 다른 출현빈도를 보였다. ND2의 methionine codon으로 Large White와 Landrace는 각각 전 개체에서 ATA와 ATT 서열로 확인되었다. 다른 3 품종(Berkshire, Duroc, Hampshire)의 경우는 두 서열이 모두 발생하였으며, 91.9, 21.3, 60.0%의 빈도로 ATA를 보였다. 기존의 연구들에 의하면 중국재래돼지들이 모두 개시코돈 ATA를 갖는다고 보고되어 있다. 미토콘드리아 ND2 단백질의 합성과정에서 AIC가 어떤 영향을 미치는지는 설명할 수 없으나, 본 연구에서 나타난 AIC 다형성과 품종특이적인 분포양상은 돼지의 육종에 있어 모계추적을 위한 분자적 표지인자로서 이용될 수 있을 것을 사료된다.

• Advances in environmental research
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• 제3권2호
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• pp.131-149
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• 2014

Two different model selection indices, the Akaike information criterion (AIC) and the coefficient of determination ($R^2$), are used to discriminate competing isotherm equations for aqueous pollutant removal systems. The former takes into account model accuracy and complexity while the latter considers model accuracy only. The five types of isotherm shape in the Brunauer-Deming-Deming-Teller (BDDT) classification are considered. Sorption equilibrium data taken from the literature were correlated using isotherm equations with fitting parameters ranging from two to five. For the isotherm shapes of types I (favorable) and III (unfavorable), the AIC favors two-parameter equations which can easily track these simple isotherm shapes with high accuracy. The $R^2$ indicator by contrast recommends isotherm equations with more than two parameters which can provide marginally better fits than two-parameter equations. To correlate the more intricate shapes of types II (multilayer), IV (two-plateau) and V (S-shaped) isotherms, both indices favor isotherm equations with more than two parameters.

• 한국수산과학회지
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• 제52권6호
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• pp.719-724
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• 2019

This study is an extension of our previous model for a size-based fish stock assessment. In the previous model, we applied an allometric length-weight relationship (W=α·L^β) to convert lengths of fish to weights, and estimated those parameters α and β, using data about lengths and weights aggregated over years. In this study, we focused on whether consideration of temporal (e.g., year-to-year) variability in those estimates (i.e., ${\hat{\alpha}}$ and ${\hat{\beta}}$) would contributive. After calculating year-specific estimates (i.e., year-specific pairs of ${\hat{\alpha}}$ and ${\hat{\beta}}$) by applying data about lengths and weights separated by year, we evaluated the contribution of those year-specific pairs of ${\hat{\alpha}}$ and ${\hat{\beta}}$ to the performance of the size-based stock assessment model. The model with such year-to-year variability being considered (lower AIC) outperformed that with the variability being ignored (higher AIC). We illustrated this study using data on Korean chub mackerel Scomber japonicus from 2005-2017.

• 대한기계학회논문집A
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• 제36권8호
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• pp.921-927
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• 2012

신뢰성 기반 최적설계는 설계변수들의 변동을 평균이나 분산 등의 통계적 특성으로 고려하여 설계자가 원하는 신뢰도를 만족하는 해를 구한다. 신뢰도를 구하기 위한 기존의 신뢰성해석 기법들은 변수들이 연속함수로 정의되는 특정 확률분포를 따른다는 가정을 하지만 실제 문제에서 변수들은 한정적인 이산정보의 형태인 경우가 많기 때문에 변수들에 대한 가정을 하지 않고 이산정보로부터 신뢰성해석을 수행하는 것은 매우 중요하다. 본 연구에서는 후보 분포들 중에서 이산정보를 가장 잘 추정하는 분포를 결정하는 기법인 Akaike 정보척도를 이용하여 신뢰성해석 및 신뢰성 기반 최적설계를 수행하는 기법을 제안한다. 수학예제를 통해 정확성을 검증하고 철도차량 용접대차의 신뢰성 기반 최적설계에 적용하여 제안한 기법의 유용성을 확인한다.

• 응용통계연구
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• 제18권2호
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• pp.435-443
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• 2005

로지스틱 회귀모형에서 결정계수는 선형 회귀모형보다 다양하게 정의되며 그 값들도 매우 작아 로지스틱 회귀모형 평가기준으로 사용되는 통계량이 라고 할 수 없다. Liao와 McGee(2003)는 부적절한 설명변수의 추가 또는 표본크기의 변화에 민감하지 않은 두 종류의 수정 결정계수를 제안하였다. 본 연구에서는 실제자료에 적용한 로지스틱 회귀모형에서 수정 결정계수를 포함한 네 종류의 결정계수들을 변수선택의 기준으로 사용하여 기존의 변수선택 방법인 전진선택, 후진제거, 단계적 선택방법, AIC 통계량 등을 사용한 방법들과 비교하여 그 적절함과 효율성을 토론한다.

• Spatial Information Research
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• 제23권5호
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• pp.65-73
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• 2015

서울시는 강북의 노후화 및 강남과 강북의 경제 불균형을 해소하고자 뉴타운 사업을 시행하였고, 이에 따라 은평구는 시범지구로 지정되었으며 2013년 최종적으로 사업이 완료되었다. 이에 본 연구는 은평구에서 진행된 뉴타운 사업에 따라 발전된 사회적, 경제적 요소들이 지가에 미치는 영향의 정도를 공간 효과를 반영한 지리가중회귀모델을 이용하여 분석하였다. 분석결과 기존의 지가분석에서 주로 이용된 선형회귀모델에 비해 높은 설명력을 가지고 있었으며, AIC값과 잔차의 Moran'I를 통해 좀 더 적합한 모델로 판정하였다. 또한 지역적으로 회귀계수의 차이가 있었으며 부호가 다르게 나타나는 경우도 있어 선형회귀모델을 통한 전역적인 분석방법보다 자세한 설명이 가능해졌다. 추후 은평구 개발에 있어 공간적 특성을 고려하여 지역을 개발한다면 실효성 강화에 도움이 될 수 있을 것으로 판단된다.

• 대한가정학회지
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• 제33권1호
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• pp.169-180
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• 1995

To determine the effects of guar suksolgi on blood glucose and lipids in type-ll diabetic subjects, a piece of guar suksolgi(36.3g, 54Kcal) was administered to eight patients for 3 weeks every meal. No significant differences occured indietary intakes and body weight before and after the treatment. Fasting blood glucose levels were decreased from 132.38mg/dI to 114.75mg/dI after the treatment, but not statistically significant. Blood TG levels were increased from 159.13mg/dI to 175.00mg/dI after the treatment, but not statistically significant. Excluding one patient who had extremely high TG level, blood TG levels tended to be decreased from 148.00mg/dI to 121.00mg/dI. TC LDL-c, HDL-c levels were decreased after the treatment, but not statistically significant. HbAIC concentrations were decreased from 8.54mg/kI to 7.80mg/dI after the treatment, but not statistically significant. In the case of three patients who had had normal fasting blood glucose levels, blood glucose levels tended to be decreased at postprandial 30, 60 minutes, and blood insulin levels tended to be decreased at postprandial 30, 60, 90, 120 minutes, although none of the levels were statistically significant. Therefore, if guar suksolgi is adinistered to type-ll diabetic subjects being more hyperglycemic than our patients, their blood glucose and lipids will be decreased significantly.

• Asian-Australasian Journal of Animal Sciences
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• 제32권12호
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• pp.1836-1843
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• 2019

Objective: Social genetic effects (SGE) are an important genetic component for growth, group productivity, and welfare in pigs. The present study was conducted to evaluate i) the feasibility of the single-step genomic best linear unbiased prediction (ssGBLUP) approach with the inclusion of SGE in the model in pigs, and ii) the changes in the contribution of heritable SGE to the phenotypic variance with different scaling ${\omega}$ constants for genomic relationships. Methods: The dataset included performance tested growth rate records (average daily gain) from 13,166 and 21,762 pigs Landrace (LR) and Yorkshire (YS), respectively. A total of 1,041 (LR) and 964 (YS) pigs were genotyped using the Illumina PorcineSNP60 v2 BeadChip panel. With the BLUPF90 software package, genetic parameters were estimated using a modified animal model for competitive traits. Giving a fixed weight to pedigree relationships (${\tau}:1$), several weights (${\omega}_{xx}$, 0.1 to 1.0; with a 0.1 interval) were scaled with the genomic relationship for best model fit with Akaike information criterion (AIC). Results: The genetic variances and total heritability estimates ($T^2$) were mostly higher with ssGBLUP than in the pedigree-based analysis. The model AIC value increased with any level of ${\omega}$ other than 0.6 and 0.5 in LR and YS, respectively, indicating the worse fit of those models. The theoretical accuracies of direct and social breeding value were increased by decreasing ${\omega}$ in both breeds, indicating the better accuracy of ${\omega}_{0.1}$ models. Therefore, the optimal values of ${\omega}$ to minimize AIC and to increase theoretical accuracy were 0.6 in LR and 0.5 in YS. Conclusion: In conclusion, single-step ssGBLUP model fitting SGE showed significant improvement in accuracy compared with the pedigree-based analysis method; therefore, it could be implemented in a pig population for genomic selection based on SGE, especially in South Korean populations, with appropriate further adjustment of tuning parameters for relationship matrices.

• Safety and Health at Work
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• 제15권1호
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• pp.59-65
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• 2024

Background: Different job strain formulations based on the Job Demand-Control model have been developed. This study evaluated longitudinal associations between job strain and psychological distress and whether associations were influenced by six formulations of job strain, including quadrant (original and simplified), subtraction, quotient, logarithm quotient, and quartile based on quotient, in randomly selected Japanese workers. Methods: Data were from waves I and II of the Survey of Midlife in Japan (MIDJA), with a 4-year followup period. The study sample consisted of 412 participants working at baseline and had complete data on variables of interest. Associations between job strain at baseline and psychological distress at follow-up were assessed via multivariable linear regression, and results were expressed as β coefficients and 95% confidence intervals including R² and Akaike information criterion (AIC) evaluation. Results: Crude models revealed that job strain formulations explained 6.93-10.30% of variance. The AIC ranged from 1475.87 to 1489.12. After accounting for sociodemographic and behavioral factors and psychological distress at baseline, fully-adjusted models indicated significant associations between all job strain formulations at baseline and psychological distress at follow-up: original quadrant (β: 1.16, 95% CI: 0.12, 2.21), simplified quadrant (β: 1.01, 95% CI: 0.18, 1.85), subtraction (β: 0.39, 95% CI: 0.09, 0.70), quotient (β: 0.37, 95% CI: 0.08, 0.67), logarithm quotient (β: 0.42, 95% CI: 0.12, 0.72), and quartile based on quotient (β: 1.22, 95% CI: 0.36, 2.08). Conclusion: Six job strain formulations showed robust predictive power regarding psychological distress over 4 years among Japanese workers.