• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2021년도 춘계학술발표대회
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• pp.505-508
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• 2021

반도체 회로의 미세화로 단위 공정이 증가하면 TAT(turn-around time) 증가에 따른 제조 비용이 늘어난다. 반도체 공정 중 포토 공정은 마스크의 회로를 웨이퍼에 전사하는 공정으로 전사를 담당하는 노광장비의 성능에 의해 회로의 정확성이 결정된다. 이런 정확성을 검증하는 계측공정은 회로의 미세화가 진행될수록 필요성은 증가하나 TAT 증가의 주된 요인으로 최근 기계학습을 사용한 다양한 예측 모형들의 개발로 계측 결과를 예측하는 실험들이 진행되고 있다. 본 논문은 노광장비 센서들의 이상값을 감지하여 분류 후 계측공정을 진행하는 LFDC(Lithography Fault Detection and Classification) 시스템의 문제인 분류 성능이 떨어지는 것을 해결하기 위해 XGBoost를 사용하여 계측공정을 진행하지 않고 노광장비 센서의 이상값을 학습된 학습기를 통해 분류하여 포토 공정을 재진행하거나 다음 공정을 진행하는 방법을 실험하였다. 실험에서 사용된 계측 결과 예측 모형은 89%의 정확도를 확보하였고 반도체 데이터 특성인 심각한 불균형의 데이터에 대해서도 같은 정확도를 얻었다. 이런 결과는 노광장비 센서들의 이상값에 대해 89%는 정상으로 판단하였고 정상으로 판단한 웨이퍼를 실제 계측 시 예측과 같은 결과를 얻었다. 계측 결과 예측 모형을 사용하면 실제 계측을 진행하지 않고 노광장비 센서들의 이상값에 대한 판정을 할 수 있어 TAT 단축으로 제조 비용감소, 계측 장비 부하 감소 및 효율 향상을 할 수 있다. 하지만 본 논문에서는 90%의 성능을 보이는 계측 결과 예측 모형으로 여전히 10%에 대해서는 실제 계측이 필요한 문제에 대해 추후 더 연구가 필요하다.

• 분석과학
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• 제37권2호
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• pp.87-97
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• 2024

The appropriate intake of fluoride (F^-) is beneficial to human health; however, the over-consumption can result in various potentially harmful effects. This study compared different colorimetric reagents, i.e., aluminium-xylenol orange (Al-XO), zirconium-xylenol orange (Zr-XO), and zirconium-alizarin red S (Zr-ARS), for fluoride measurements by the UV-Vis, in terms of reaction mechanisms, method sensitivity, and interferences from aluminium and ferric ions. The colorimetric procedures were optimized, and the analytical methods were evaluated. The goodness of linearity (R² > 0.998) was obtained for all three assays within the concentration range of 1.0-20.0 mg/L fluoride in deionized water, in which the method sensitivity followed the descending order of Zr-XO > Al-XO > Zr-ARS. The Zr-XO was applied for determining the fluoride in different tea extracts in water (90 ℃ and 60-minute-brewing) and black tea demonstrated the highest fluoride content (3.0-3.6 mg/L). The effects of brewing time and temperature on the release of fluoride in the tea extracts were also investigated, indicating these are critical factors for the fluoride extraction. This study highlighted the application potentials of the UV-Vis measurement as a simple, convenient, and cheap analytical approach and discussed different colorimetric reagents used for fluoride determination in tea extracts in the context that the UV-Vis spectrophotometers are commonly equipped in most laboratories.

• 생명과학회지
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• 제20권5호
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• pp.697-702
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• 2010

2007년 전국 10개의 일반 양돈장에서 다양한 일령의 돼지 578두를 채혈하여 Rose Bengal test 진단액으로 스크리닝을 하고, 양성 혈청에 대해서는 시험관응집반응과 C-ELISA를 적용하여 브루셀라병 항체 분포도 양상과 브루셀라 교차반응 유발균의 분리를 시도하여 다음과 같은 결론을 얻었다. 돼지에서 브루셀라병 Rose Bengal 스크리닝 결과, 10주령 미만(양성률; 14.6%, 95% CI; 10.1-19.1)자돈보다 10주령에서 17주령 미만(양성률; 31.3%, 95% CI; 22.8-39.8)과 17주령 이상(양성률; 30.4%, 95% CI; 34.3-36.4)의 돼지에서 양성률이 유의성 있게 높았다(p<0.05). 따라서 검사돈 중 139두 (24.0%)에서 Rose Bengal test 양성반응이 나타났다. 양돈장별 Rose Bengal test 양성률 조사에서 6개 양돈장이 10% 미만의 양성률을 보였고, 2개 양돈장에서는 70% 이상의 높은 양성률이 관찰되었다. Rose Bengal test 양성 혈청 139건을 시험관응집반응과 C-ELISA에 적용한 결과, 시험관응집반응에서 100배 이상의 양성이 48건(34.5%)이었으나 C-ELISA에서는 전 두수 음성으로 나타나 돼지 혈청에 대해서는 시험관응집반응 성적과 C-ELISA 성적에 많은 차이가 있었다. 시험관응집반응에서 높은 항체가를 보인 돼지의 직장 swab 시료(n=26)에서 브루셀라 균과 교차반응을 유발하는 균종에 대해 균분리를 실시한 결과 E. coli O157:H7, Salmonella N group은 분리되지 않았으나 Y. enterocolitica O:9은 7건(26.9%)이 분리되었다.

• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.739-748
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• 2020

The study aims to estimate the effect of current ratio (CR), current liability to inventory (CLI), total asset turnover (TAT), net profit margin (NPM), sales growth (SG), and company size (FS) on profit growth (PG). The research population was 18 companies in the Food and Beverage (F&B) sector listed on the Indonesia Stock Exchange (IDX) from 2014-2018. The data estimation method uses the common effect panel data regression model. The empirical findings show that the CR and CLI ratios have a negative effect on PG, while the TAT, NPM, and SG ratios have a positive effect. Company size is a factor that does not affect the growth of company profits. The results of the study imply that an increase in company profits can be achieved if the company operates efficiently and with low liquidity to encourage higher sales growth. The limitations of the research are as follows: first, this research considers only one type of industry, hence the results of this study would not be the same if applied to another type of industry. Second, the author observes profit growth by using the company's financial ratios and size and ignores other factors that may affect profit growth, for example, the number of employees, total net sales, and market capitalization.

• 대한의생명과학회지
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• 제10권3호
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• pp.187-194
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• 2004

A short peptide corresponding to the nuclear localization signal (NLS) of human immunodeficiency virus (HIV)-l Tat protein, Arg-Lys-Lys-Arg-Arg-Gln-Arg-Arg-Arg, was employed to improve the efficiency of cellular uptake of nucleic acids. The peptide was first mixed with a reporter plasmid and then with cationic liposomes to form a tripartite complex of DNA/peptide/liposomes (DPL). Transfection efficiency of the DPL complex was compared with that of the conventional DNA/liposomes (DL) complex. When the DPL complex was formed with various cationic liposomes, DOTAP/DOPE (DP) liposome exhibited superior transfection efficiency to other liposomes tested in vitro. With the inclusion of the peptide, the DPL complex showed much enhanced transfection in various cancer cell lines. Particularly, transfection of the DPL complex in serum increased cellular uptake of a transgene up to 2 fold when compared with that in a serum free condition. Further, when the DPL complex was infused through the ureteric route of a rat, transfection efficiency was shown to be better in reporter gene expression than that obtained with the DL complex. This study shows that the DPL complex that is easy to formulate can be employed for much enhanced cellular uptake of a trans gene.

• Journal of Microbiology and Biotechnology
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• 제25권7호
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• pp.963-977
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• 2015

The well-characterized gram-positive bacterium Bacillus subtilis is an outstanding industrial candidate for protein expression owing to its single membrane and high capacity of secretion, simplifying the downstream processing of secretory proteins. During the last few years, there has been continuous progress in the illustration of secretion mechanisms and application of this robust host in various fields of life science, such as enzyme production, feed additives, and food and pharmaceutical industries. Here, we review the developments of Bacillus subtilis as a highly promising expression system illuminating strong chemical- and temperatureinducible and other types of promoters, strategies for ribosome-binding-site utilization, and the novel approach of signal peptide selection. Furthermore, we outline the main steps of the Sec pathway and the relevant elements as well as their interactions. In addition, we introduce the latest discoveries of Tat-related complex structures and functions and the countless applications of this full-folded protein secretion pathway. This review also lists some of the current understandings of ATP-binding cassette transporters. According to the extensive knowledge on the genetic modification strategies and molecular biology of Bacillus subtilis, we propose some suggestions and strategies for improving the yield of intended productions. We expect this to promote striking future developments in the optimization and application of this bacterium.

• Toxicological Research
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• 제3권2호
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• pp.73-80
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• 1987

Primary cultures of adult rat hepatocytes were used to study the cytotoxicity of D-galactosamine. Hepatocytes were isolated by a collagenase perfusion technique and maintained as monolayers in serum-free medium on collagen-coated culture dishes. Treatment of galactosamine to the culture markedly inhibited the uptake of ${\alpha}$-aminoisobutyric acid (AIB) inducible with glucagon and dexamethasone. At0.1 mM of galactosamine, AIB uptake was inhibited significantly when treated for 12 hr. At higher doses (0.25, 0.5 and 1.0mM), a significant inhibition was noticed after 1 hr exposure. Generally the magnitude of the inhibition was related to the dose and treatment time of galactosamine. Treatment of galactosamine also produced a dose- and treatment time-related suppression of the tyrosine aminotransferase (TAT) induction caused by dexamethasone. Meanwhile, uptake of ouabain was not affected by the treatment of galactosamine. The viability of the hepatocytes was decreased only slightly by the treatment of galactosamine; more than 87% of the cells excluded tryphane blue when treated 1 mM galactosamine for 12 hr. Galactosamine induced depressions of AIB uptake and TAT activity were prevented by the simultaneous addition of uridine to the culture. D-Galactosamine, cytotoxicity, hepatocytes culture, ${\alpha}$-aminoisobutyric acid uptake, tyrosine aminotransferase.

• Current Optics and Photonics
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• 제1권2호
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• pp.118-124
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• 2017

Color rendering index (CRI) and luminous efficacy (LE) are two key performance factors of white LEDs (WLED). While most recent works in optics focus on methodology to improve these factors, little attention has been dedicated to chemical composition of materials. This paper studies the effect of $Sr_{2.4}1F_{2.59}B_{20.03}O_{74.8}:Eu_{0.12},Sm_{0.048}$ phosphor (SrSm), in terms of concentration and particle size on CRI and LE of 8500 K - WLEDs. Importantly, the molar mass of the componential ions in SrSm are calculated to shed light on the connection between the chemical composition of the material of interest and the performance of WLEDs. Results show that CRI can be improved to a value of around 86 by boosting red-light components in WLEDs, for all 3 major configurations: conformal, in-cup, and remote phosphor. CRI value tends to decrease with larger size of particles, while LE value goes in the reverse direction. On the other hand, both CRI and LE appear to be reduced at higher concentration of SrSm. This light attenuation is analyzed by using the Lambert-Beer law and Mie-scattering theory.

• 한국동물위생학회지
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• 제30권3호
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• pp.385-391
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• 2007

A novel enzyme linked immunosorbent assay (ELISA) is described and compared with other established serologic tests for bovine brucellosis, namely the rose bengal test (RBT), the complement fixation test (CFT), and the tube agglutination test (TAT) approved and used in Korea. A total of 109 bovine serum samples were tested using all the 4 assays and analyzed as to specificity, sensitivity, reproducibility and predictive value. The ELISA showed 100% agreement with the CFT. The least agreement between ELISA was observed with the TAT. The agreement between the ELISA and RBT was not significantly different from that observed between the CFT and the ELISA. It is concluded that the new assay would be a good candidate for routine serologic survey for brucellosis in Korea. A protocol combining the ELISA and the CFT would increase the power for detection of serologically positive individuals and herds.

• 분석과학
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• 제36권5호
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• pp.205-215
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• 2023

In the present study, an analytical method was proposed for detecting trifluralin in aquatic products at trace concentrations. The method employed QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) and gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) as the sample preparation and measurement, respectively. The effect of the aqueous phase volume used in the QuEChERS was demonstrated, and the ratio of 10:10 (mL) between water and acetonitrile phase was used for 5 g of sample. Besides, dSPE using C18 and primary-secondary amine (PSA) was applied to remove the potential interferences from the food matrices, indicating no remarkable analyte loss. The linear range was built up from 0.50 ㎍ L^-1 to 3.0 ㎍ L^-1 (R² = 0.9993). Other criteria, i.e., repeatability (RSD_r = 0.86-1.96 %), reproducibility (RSD_R = 1.09-2.01 %), and recovery (over 90 %), were in accordance with Appendix F of AOAC (2016) for method performance. Although no trifluralin was detected for the commercial samples (fish, shrimp, and breaded shrimp), the spiked samples performed favorable recoveries and precision.