• Economic and Environmental Geology
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• v.43 no.5
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• pp.523-528
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• 2010

With the financial crisis from USA had negative impacts on the real economy, base metals price on LME was downward in 4 quarter of 2008. Following the deepest global downturn in recent history, economic growth solidified and broadened to advanced countries and simultaneously the price of base metal on LME showed a rising curve over 2009. There are three factors supported an upward tendency of base metal's price. The First factor is the US economy recovery, the second factor is the weak dollar, the third factor is the chinese base metal demand. Among the factors, the last one is a major factor. Therefore, this study analyze the factor of the movement of price of base metal with linear regression analysis. The result of analysis show that the chinese GDP growth has effect on the recent upward base metal price. Despite the result, the upward movement is difficult to be sustained without the full recovery of advanced economies.

• Journal of Life Science
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• v.29 no.10
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• pp.1104-1110
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• 2019

Recently, there has been an increase in the elderly population of the world. Consequently, bone metabolic diseases such as osteoporosis are emerging as a social problem. Osteoclasts play a role in bone resorption, and osteoporosis is induced when bone resorption occurs excessively. Because currently used bone resorption inhibitors may cause side effects when used for a long period of time, it is necessary to develop a new material that effectively inhibits osteoclast differentiation. This study aimed to confirm the inhibitory effect of ethanol extract of Locusta migratoria on RANKL-induced osteoclast differentiation and its mechanism. The toxicity and proliferation effects of LME on RAW264.7 osteoclasts were measured by an MTS assay. There was no cytotoxicity or proliferation when the osteoclasts were treated with up to $2,000{\mu}g/ml$ of LME. In order to confirm the effect of LME on the differentiation of osteoclasts, osteoclasts were treated with RANKL alone or with LME for 3 days. As a result of a TRAP (tartrate-resistant acid phosphatase) assay, the increasing osteoclast differentiation by RANKL decreased in a concentration-dependent manner with the treatment of LME. In addition, LME suppressed the expression of differentiation-related marker genes (TRAP, RANK, NFATc1, and CK) and proteins (NFATc1 and c-Src) that had been increased by RANKL. Also, LME influenced the $NF-{\kappa}B$, ERK and JNK signaling pathways, resulting in the inhibition of osteoclast differentiation. These results suggest that LME may be used as a novel functional material for the prevention and treatment of osteoporosis by playing a role in inhibiting bone absorption.

• Journal of Powder Materials
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• v.28 no.2
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• pp.91-96
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• 2021

Rare earth magnets with excellent magnetic properties are indispensable in the electric device, wind turbine, and e-mobility industries. The demand for the development of eco-friendly recycling techniques has increased to realize sustainable green technology, and the supply of rare earth resources, which are critical for the production of permanent magnets, are limited. Liquid metal extraction (LME), which is a type of pyrometallurgical recycling, is known to selectively extract the metal forms of rare earth elements. Although several studies have been carried out on the formation of intermetallic compounds and oxides, the effect of oxide formation on the extraction efficiency in the LME process remains unknown. In this study, microstructural and phase analyses are conducted to confirm the oxidation behavior of magnets pulverized by a jaw crusher. The LME process is performed with pulverized scrap, and extraction percentages are calculated to confirm the effect of the oxide phases on the extraction of Dy during the reaction. During the L ME process, Nd is completely extracted after 6 h, while Dy remains as Dy₂Fe₁₇ and Dy-oxide. Because the decomposition rate of Dy₂Fe₁₇ is faster than the reduction rate of Dy-oxide, the importance of controlling Dy-oxide on Dy extraction is confirmed.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.10
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• pp.1340-1347
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• 2010

To study the effects of ${\alpha}$-galactosidase (${\alpha}$-Gal) supplementation on performance and energy metabolism, 216 Arbor Acres male broilers were placed in 36 cages of 6 birds each and allotted to 4 diets for 42 d, with 0-21 d as starter period and 22-42 d as grower period. The 4 diets were based on corn non-dehulled soybean meal in a $2{\times}2$ factorial arrangement, with 2 levels of ${\alpha}$-Gal (0 vs. 60 U/kg feed) and 2 levels of ME (normal metabolizable energy (NME) and low metabolizable energy (LME)). Bird performance was obtained at 21 and 42 d of age with samples of feces collected for nutrient digestibility from 19-21 d and 40-42 d. At 21 and 42 d, 1 bird from 6 cages of each treatment was killed to determine liver weight, intestinal pH and chyme viscosity. With the addition of ${\alpha}$-Gal the 42 d body weight (BW) and 0-42 d average daily gain (ADG) were significantly improved (p<0.05). Average daily feed intake (ADFI) of birds fed the LME diet was significantly increased compared to those fed the NME diet during starter (p<0.01) and grower (p<0.05) periods and overall (p<0.01). There was an interaction of ${\alpha}-Gal{\times}ME$ on 0-21 d ADFI (p<0.01). Supplementation of ${\alpha}$-Gal significantly improved (p<0.01) feed efficiency during the grower period and overall. Feed efficiency of birds fed the LME diet was significantly decreased (p<0.05) compared to those fed the NME diet during the starter period and overall. With the addition of ${\alpha}$-Gal apparent metabolizable energy (AME) was improved (p<0.01) by 2.1% and 1.8% during starter and grower periods, respectively. There was a main effect (p<0.05) of ${\alpha}$-Gal on the digestion of neutral detergent fiber (NDF) during the starter period and crude protein (CP), NDF and acid detergent fiber (ADF) during the grower period. With the addition of ${\alpha}$-Gal, the relative weight of liver was reduced (p<0.01) during the two phases. The duodenal and jejunal pH were significantly decreased (p<0.01) with the supplementation of ${\alpha}$at the two phases. ${\alpha}$-Gal addition reduced (p<0.01) chyme viscosity of the ileum during the starter and grower periods. Overall, ${\alpha}$-Gal showed a major effect on nutrient efficiency, improved ADG and feed efficiency, whereas LME decreased feed efficiency. The incorporation of ${\alpha}$-Gal into a LME diet could at least partially offset ME deficiency of non-dehulled soybean meal.

• Journal of Life Science
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• v.28 no.12
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• pp.1448-1454
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• 2018

Insects have been investigated as a novel source of food and biomaterial in several recent studies. However, their osteoblastogenic cell activity has not been sufficiently researched and so, to investigate the potential of this natural material for promoting osteoblastogenesis, we studied the activity of Locusta migratoria ethanol extract (LME) on MG-63 pre-osteoblast cells. The cytotoxicity and proliferation effects of LME on MG-63 cells were measured by MTS assay, and there was no cytotoxicity up to $1,000{\mu}g/ml$. With LME treatment of 500 and $1,000{\mu}g/ml$ for 48 hr, cell proliferation increased to 105% and 116% versus control, respectively. The osteoblastogenic activity of the LME was measured through alkaline phosphatase (ALP) staining at three and five days. As a result, both 500 and $1,000{\mu}g/ml$ LME concentrations were seen to increase ALP activity by more than three times compared with control at three and five days. In addition, the expression level of the osteogenic markers ALP and RUNX2 was markedly increased after LME treatment. These results demonstrate that Locusta migratoria ethanol extract promotes osteoblastogenesis as evidenced by the increased osteogenic markers and suggest that LME may be a potential agent for bone formation and osteoporosis prevention.

• Proceedings of the KWS Conference
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• 1998.10a
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• pp.71-72
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• 1998

• Mineral and Industry
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• v.28
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• pp.14-22
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• 2015

• 한국데이터정보과학회:학술대회논문집
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• 2003.10a
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• pp.139-145
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• 2003

본 논문에서는 강수 자료의 예측에 사용되는 3-모수 카파 분포(KD3)에서의 모수 추정 방법을 알아보고 시뮬레이션을 통하여 모수 추정 방법에 따른 성능을 비교해 보았다. 이 분포의 모수 $\alpha,\;\beta,\;\mu$를 추정하기 위하여 적률추정법(MME), L-적률 추정법(LME), 최우추정법(MLE)을 적용하였다. 소표본의 경우뿐만 아니라 대표본의 경우에도 시뮬레이션을 통하여 추정법들의 성능을 비교하였다. 적률 추정법과 L-적률 추정법에서는 제약조건 하에서의 1차원 Newton-Raphson방법을 수정하여 이용하였다. MSE를 기준으로 한 시뮬레이션 결과, KD3의 모수 추정에 있어서 표본의 크기가 100보다 작으면 LME의 적용을 추천하고 표본의 크기가 100이상이면 MLE를 추천한다.

• Journal of Korea Foundry Society
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• v.30 no.6
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• pp.201-204
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• 2010

• The Journal of the Convergence on Culture Technology
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• v.8 no.2
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• pp.315-319
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• 2022

This study investigates longitudinal writing development in terms of syntactic complexity using linear mixed effects (LME) model. This study employs essays written by four case study participants. Participants voluntarily wrote essays outside of the classroom and submitted the first and second drafts, after reflecting on the automated writing evaluation feedback (i.e., Criterion) every month over one year. A total of 48 first drafts were analyzed and syntactic complexity features were selected from Syntactic Complexity Analyzer. Results of LME showed that there was a significant positive linear relationship between time and mean length of T-unit and also between time and the ratio of dependent clauses to independent clauses, indicating that case study participants wrote longer T-units and also a higher proportion of dependent clauses over one year.