• 농업과학연구
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• 제48권1호
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• pp.95-101
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• 2021

This study investigated the influence of sodium stearoyl-2-lactylate (SSL) emulsifier on the growth performance and nutrient digestibility of growing pigs. For this 56-day long-duration experiment, 80 heads of cross-bred ([Landrace × Yorkshire] × Duroc) pigs with an initial body weight of 23.80 ± 4.87 kg were divided into two (2) treatment groups each fed a different diet: with and without an emulsifier. Each treatment group had 8 replication pens with 5 pigs per pen. Feed treatments were as follows: 1) CON: Basal diet, and 2) SSL: CON + 0.05% SSL. Body weight (BW), average daily gain (ADG), and feed conversion ratio (FCR) were measured for three periods: 0 - 4, 5 - 8, and 0 - 8 weeks. The nutrient digestibility parameters consisting of dry matter (DM) digestibility and nitrogen (N) digestibility were calculated on the 4^th and 8^th week. Based on the results, the SSL supplementation did not show any significant influence on the growth performance parameters during the 0 to 4 and 5 to 8 week phases. For the overall performance, only the FCR (p = 0.048) was significantly different in the emulsifier fed group (SSL) compared to the CON group (T1). DM and N digestibility was also not influenced by the SSL addition in the growing pig diet. Overall, the SSL supplementation showed a limited effect on the growth performance of growing pigs.

• 대한환경공학회지
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• 제22권1호
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• pp.11-19
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• 2000

생물학적 폐수처리장의 효율을 정확하게 예측하기 위해서는 생물학적 동력학 계수와 화학양론적 계수를 반드시 추정하여야만 한다. 본 연구에서는 생물학적 동력학 계수를 추정하는 실험적 방법과 그 이론적 배경이 논의되었다. 또한 생물학적 동력학 계수 추정을 위해 신소이용률(Oxygen Uptake Rate, OUR)을 이용한 회분식 실험을 실시하였다. 호기성 상태에서 종속영양미생물과 독립영양미생물의 생물학적 동력학 계수를 추정하기 위한 간단한 방법이 기술되어 있다. 생물학적 동력학 계수 추정시 해석상의 부정확성 때문에 COD와 VSS농도를 이용하지 않고 산소이용률을 미생물 성장 자료로 변환하여 사용하였다. 종속영양미생물의 최대비성장율, 생산계수, 반속도상수, 사멸율을 산소이용률을 사용하여 추정하였다. 또한 독립영양미생물의 최대비성장율은 $NO_3{^-}$ 농도의 증가율로부터 추정하였다. 본 연구의 목적은 회분식 반응조에서 산소이용률을 이용해 종속영양미생물과 독립영양미생물의 생물학적 동력학 계수를 정확하고 간편하게 추정하는데 있다. 이러한 산소이용률을 이용한 생물학적 동력학 계수 추정 방법이 복잡한 활성슬러지 모델링에 도움을 줄 것으로 판단된다.

• 한국농림기상학회지
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• 제21권1호
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• pp.42-54
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• 2019

작물 생육모델이 요구하는 다양한 모수들 중 품종의 유전적 특성을 나타내기 위한 품종모수는 개별 품종별로 추정되어야 한다. 모수 추정을 위해 상당한 비용과 노력이 요구되는 고품질의 상세한 생육자료를 사용하여 하나, 자료의 가용성이 대체로 낮기 때문에, 품질이 낮더라도 쉽게 얻을 수 있는 자료를 이용하여 품종모수를 추정하는 방식의 가능성과 문제점을 파악하는 것이 필요하다. 본 연구에서는 신품종개발 공동연구 보고서로부터 2005년부터 2016년까지 신동진 벼에 대한 자료들을 수집하고, 이를 사용하여 신동진 벼의 품종모수를 추정하였다. 또한, 추정된 모수를 사용한 생육모의 결과들을 활용하여 개별 항목에 대한 신뢰도를 평가하였다. 출수기에 대해서는 RMSE가 대부분 3일 이하로, 비교적 정확하게 모의할 수 있는 모수가 추정되었다. 수량에 대해서는 RMSE가 대부분 700 kg/ha 이하로 작게 나타났으나, 결정계수가 대부분 0.1 이하로 나타나, 신뢰도 높은 모수가 추정된 것으로 판단하기 어려웠다. 이러한 결과는 작물이 자라는 중간 단계의 생육 관측자료를 비교하지 못하였기 때문일 것으로 사료되었다. 따라서, 모수의 신뢰도를 높이기 위해 시기별 생육자료의 측정이 필요할 것이며, 이를 위한 시간과 비용을 절감하기 위한 기법이 개발되어야 할 것이다. 기상자료와 실제 기상과의 차이로 인한 오차를 줄이기 위해서는 방재기상자료와 같은 가까운 기상자료를 사용하거나, 공간내삽 등의 방법을 활용하여야 할 것이다. 또한, 자연재해와 같이 모델에서 고려할 수 없는 요인으로 인해 영향을 받은 자료는 제외하는 것이 모수의 신뢰도를 높일 수 있을 것이다. 본 연구에서 제시한 출수기와 수량 추정치의 오차가 작았던 모수들의 범위는 이후 연구에서 신동진과 유사한 품종의 모수를 추정할 때 참고자료로 사용될 수 있을 것이다.

• 대한치과교정학회지
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• 제50권2호
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• pp.108-119
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• 2020

Objective: The primary objective of this study was to quantitatively analyze the bone parameters (thickness and density) at four different interdental areas from the distal region of the canine to the mesial region of the second molar in the maxilla and the mandible. The secondary aim was to compare and contrast the bone parameters at these specific locations in terms of sex, growth status, and facial type. Methods: This retrospective cone-beam computed tomography (CBCT) study reviewed 290 CBCT images of patients seeking orthodontic treatment. Cortical bone thickness in millimeters (mm) and density in pixel intensity value were measured for the regions (1) between the canine and first premolar, (2) between the first and second premolars, (3) between the second premolar and first molar, and (4) between the first and second molars. At each location, the bone thickness and density were measured at distances of 2, 6, and 10 mm from the alveolar crest. Results: The sex comparison (male vs. female) in cortical bone thickness showed no significant difference (p > 0.001). The bone density in growing subjects was significantly (p < 0.001) lower than that in non-growing subjects for most locations. There was no significant difference (p > 0.001) in bone parameters in relation to facial pattern in the maxilla and mandible for most sites. Conclusions: There was no significant sex-related difference in cortical bone thickness. The buccal cortical bone density was higher in females than in males. Bone parameters were similar for subjects with hyperdivergent, hypodivergent, and normodivergent facial patterns.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.26-26
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• 2009

Vertically aligned arrays of mm-long multi-walled carbon nanotubes (MWCNTs) on Si substrates have been synthesized by water-assisted thermal chemical vapor deposition (CVD). The growth of CNTs was investigated by changing the experimental parameters such as growth temperature, growth time, gas composition, annealing time, catalyst thickness, and Al underlayer thickness. The 0.5-nm-thick Fe served as catalyst, underneath which Al was coated as a catalyst support as well as a diffusion barrier on the Si substrate. We grew CNTs by adding a little amount of water vapor to enhance the activity and the lifetime of the catalyst. Al was very good at producing the nm-size catalyst particles by preventing "Ostwald ripening". The Al underlayer was varied over the range of 15~40 nm in thickness. The optimum conditions for the synthesis parameters were as follows: pressure of 95 torr, growth temperature of $815^{\circ}C$, growth for 30 min, 60 sccm Ar + 60 sccm $H_2$ + 20 sccm $C_2H_2$. The water vapor also had a great effect on the growth of CNTs. CNTs grew 5.03 mm long for 30 min with the water vapor added while CNTs were 1.73 mm long without water vapor at the same condition. As-grown CNTs were characterized by using scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. High-resolution transmission electron microscopy showed that the as-grown CNTs were of ~3 graphitic walls and ~6.6 nm in diameter.

• 한국신뢰성학회지:신뢰성응용연구
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• 제14권2호
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• pp.129-136
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• 2014

Reliability test is focusing to detect the unexpected reliability failure and solve them for the high quality of products. The test data should be used to assess and project the current level of interesting product reliability and so it is very important to have the accurately assessing methodology with test data. There are two type of trend for test data as constant and changing one during testing and this paper shows the difference in the assessing results of these two cases. There is less information how to define the existence of reliability growth rate changing and calculate the parameters of the reliability growth models to make an accurate assessment with such condition, so i established the process and mathematical model to calculate the parameters at such condition to make reliability growth curve with high Goodness of Fit. I validated the new method with the data made from Monte Carlo Simulation and case from Demko (1993). Even the assessed result with the new methodology may be different with the case by case because of very diversity in test condition and testing product quality, but the process and method founded in this research can be applied to any case using Duane and AMSAA model for their test data assessment. I also present the evaluation method to see the effectiveness with new one which is a conventional knowledge and not popular to use, so it is possible to compare the results with the newly presented and conventional method for better business decision.

• Environmental Analysis Health and Toxicology
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• 제23권2호
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• pp.101-112
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• 2008

Effects of various concentrations of copper on growth change of blue-greenalgae Anabaena flos-aquae were studied. There was significant differences among cultures treated with various concentrations of copper in growth of algae with parameters of cell numbers, specific growth rate (SGR) and chlorophyll contents. Algal growth and SGR were inhibited on by effect of various concentrations of copper more than without copper (ANOVA, F=34.69 p<0.001, F=114.89, p<0.001). The SGRs of various concentrations of copper in media were higher than without copper on 8 days after copper treated. The mean of chlorophyll contents was 1.978 ${\mu}g{\cdot}mL^{-1}$ and 1.648 ${\mu}g{\cdot}mL^{-1}$, respectively, while those of algae in culture without copper was 3.179 ${\mu}g{\cdot}mL^{-1}$ (ANOVA, F=153.74, p<0.001). The cellular morphology was different between media of which copper treated and without copper. The colony of algae in media which copper treated was shorter than without copper. Effects of various concentrations of copper on growth change of blue-green-algae Anabaena flos-aquae occured variety changes of parameters of cell numbers, specific growth rate (SGR), chlorophyll contents and cellular morphology on growth of algae.

• 한국항공우주학회지
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• 제47권10호
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• pp.747-752
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• 2019

신뢰성 성장 시험을 수행하며 획득하게 되는 고장 정보와 누적 시험수행시간을 이용하면 신뢰성 성장 모델의 모수 추정이 가능하며, 모수 추정을 통해 해당 제품의 MTBF를 예측할 수 있다. 그러나 시험에 대한 비용, 시간 혹은 제품의 특성 등의 여러 제약으로 인해 고장 정보가 구간적으로 획득되거나, 획득한 고장 정보의 샘플 데이터(Sample Data)의 수가 작을 수 있다. 이는 신뢰성 성장 모델의 모수 추정의 오차를 커지게 하는 원인이 될 수 있다. 본 논문에서는 샘플 데이터의 수가 작을 경우 신뢰성 성장 모델의 모수 추정 시 베이지안 기법 기반의 모수 추정 방법의 적용에 대해 연구를 수행하였다. 시뮬레이션 결과 신뢰성 성장 모델의 모수를 추정할 때, MLE를 적용하여 추정하는 방법보다 베이지안 기법을 적용하는 방법이 추정 정확도가 높음을 확인하였다.

• Journal of Plant Biotechnology
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• 제48권2호
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• pp.115-122
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• 2021

Aspilia africana (Pers) C.D.Adams, a plant used for centuries in many African countries to treat diseases such as osteoporosis, malaria, tuberculosis, and diabetes, is of great pharmaceutical interest, yet there is limited scientific literature on its germination and growth. This research paper describes the effects of different commercial soils on the germination, growth, and chlorophyll content of A. africana. The germination parameters assessed included final germination percentage (FGP), mean germination time (MGT), and germination index (GI). Shoot length, leaf number, and fresh and dry weights were some of the parameters used to assess A. africana growth. The FGP was low and did not vary significantly; the MGT was 7 ~ 10 days; and the GI was significantly higher in PPS soil at 4.61 ± 0.332 days. Aspilia africana plants in HS:PPS soil showed the best overall growth, producing the highest mean leaf number (18.00 ± 1.129), longest mean shoot length (202.43 ± 13.451 mm), and highest mean fresh and dry weights (7.08 ± 1.061 g and 0.629 ± 0.112 g, respectively). The highest chlorophyll content in leaves of A. africana under HS:PPS conditions suggested a higher photosynthetic potential of plants in this soil. The best growth performance of A. africana in the HS:PPS soil could be attributed to a higher amount of certain mineral nutrients such as nitrogen, potassium, and phosphorus in the HS:PPS soil compared to the other soil categories. It is unclear why the FGP of A. africana was low and we recommend an exclusive study to investigate this further.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1995년도 제8회 학술발표회 논문개요집
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• pp.053-54
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• 1995