• 한국정보통신학회논문지
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• 제14권6호
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• pp.1403-1408
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• 2010

한국어 정보검색에서는 문서를 대표하는 색인어 또는 키워드로서 명사를 사용하는데, 이러한 명사 및 키워드 추출이란 문서 내에 존재하는 모든 명사를 찾아내는 작업이다. 본 논문에서는 기 구축된 사전을 이용하여 키워드를 추출하는 방법을 제시한다. 이 방법은 불필요한 연산을 줄여서 수행 시간을 단축시켰다. 그리고 대용량의 문서에서도 정확도에 크게 영향을 미치지 않으면서 명사를 추출할 수 있다. 본 논문에서는 명사의 출현 특성을 이용한 명사추출 방법 및 비감독 학습 기법에 의한 키워드 추출 방법을 제시한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 춘계학술대회
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• pp.165-166
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• 2010

명사 추출이란 문서 내에 존재하는 모든 명사를 찾아내는 작업으로서, 한국어 정보검색에서는 문서를 대표하는 색인어 또는 키워드로서 명사를 사용한다. 본 논문에서는 기 구축된 사전을 이용하여 키워드를 추출하는 방법을 제시한다. 이 방법은 불필요한 연산을 줄여서 수행 시간을 단축시켰다. 그리고 대용량의 문서에서도 정확도에 크게 영향을 미치지 않으면서 명사를 추출할 수 있다. 본 논문에서는 명사의 출현 특성을 이용한 명사 추출 방법 및 비감독 학습 기법에 의한 키워드 추출 방법을 제시한다.

• 한국재료학회지
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• 제22권11호
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• pp.636-641
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• 2012

In this study, we have investigated highly efficient nanoscale surface corrugated light emitting diodes (LEDs) for the enhancement of light extraction efficiency (LEE) of nitride semiconductor LEDs. Nanoscale indium tin oxide (ITO) surface corrugations are fabricated by using the conformal nanoimprint technique; it was possible to observe an enhancement of LEE for the ITO surface corrugated LEDs. By incorporating this novel method, we determined that the total output power of the surface corrugated LEDs were enhanced by 45.6% for patterned sapphire substrate LEDs and by 41.9% for flat c-plane substrate LEDs. The enhancement of LEE through nanoscale surface corrugations was studied using 3-dimensional Finite Different Time Domain (FDTD) calculation. From the FDTD calculations, we were able to separate the light extraction from the top and bottom sides of device. This process revealed that light extraction from the top and bottom sides of a device strongly depends on the substrate and the surface corrugation. We found that enhanced LEE could be understood through the mechanism of enhanced light transmission due to refractive index matching and the increase of light scattering from the corrugated surface. LEE calculations for the encapsulated LEDs devices also revealed that low LEE enhancement is expected after encapsulation due to the reduction of the refractive index contrast.

• 한방재활의학과학회지
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• 제30권4호
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• pp.31-39
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• 2020

Objectives Danggwisoo-san and Jakyakgamcho-tang are frequently prescribed for traffic accident patients in Korea. The aim of this study was to examine index compound analysis, antioxidant activity and amount of starch measurement by extraction method. Methods Danggwisoo-san and Jakyakgamcho-tang were extracted with water and 70% ethanol. Antioxidant activity was measured by 2,2-Diphenyl-1-picrylhydrazyl, 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and ferric reducing antioxidant power according to the standard protocol. The contents of the indicator components nodakenin, paeoniflorin, and glycyrrhizin were measured by high-performance liquid chromatography, respectively. All starches were hydrolyzed and then total D-glucose was measured and compared. Results Antioxidant activity was excellent in 70% ethanol in all assays. The index component was jagged because its solubility was different depending on the extraction solvent. Starch content was significantly lower in 70% alcohol extract than water extract. Conclusions The results of this study showed that physiological activities and components are different according to extraction conditions. Each herbal medicine has a suitable extraction solvent. Also, the difference in starch content is an object to be considered as it may affect digestion and absorption.

• 대한치과교정학회지
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• 제51권6호
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• pp.397-406
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• 2021

Objective: The purpose of this study was to evaluate the effects of self-ligating brackets (SBs) and other factors that influence orthodontic treatment outcomes. Methods: This two-armed cohort study included consecutively treated patients in a private practice. The patients were asked to choose between SBs and conventional brackets (CBs); if any patient did not have a preference, he or she was randomly allocated to the CB or SB group. All patients were treated using an identical archwire sequence. Evaluated parameters were as follows: treatment duration, number of bracket failures, poor oral hygiene, poor elastic wear, extraction, use of orthodontic mini-implants (OMI), OMI failure, American Board of Orthodontics (ABO) Discrepancy Index (DI), arch length discrepancy, and ABO Cast-Radiograph Evaluation (CRE) score. Stepwise regression analysis was performed to generate the equation for prediction of the CRE. Results: The final sample comprised 134 patients with an average age of 22.73 years. The average DI, CRE, and treatment duration were 21.81, 14.25, and 28.63 months, respectively. Analysis of covariance showed a significant difference in CRE between the CB and SB groups after adjusting for the effects of confounding variables. Stepwise regression analysis using four variables, namely extraction, SB use, poor elastic wear, and additional appliance use, could explain only 25.2% of the variance in the CRE. Conclusions: Although the CRE was significantly better for CBs than for SBs, the clinical significance of this result seems to be limited. Extraction, SB use, poor elastic wear, and additional appliance use may have significant effects on treatment outcomes.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 춘계학술회의 초록집
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• pp.16-16
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• 2010

GaN-based light-emitting diodes (LEDs) are attracting great interest as candidates for next-generation solid-state lighting, because of their long lifetime, small size, high efficacy, and low energy consumption. However, for general illumination applications, the external quantum efficiency of LEDs, determined by the internal quantum efficiency (IQE) and the light extraction efficiency, must be further increased. The IQE is determined by crystal quality and epitaxial layer structure and high value of IQE more than 70% for blue LEDs have been already reported. However, there is much room for improvement of light extraction efficiency because most of the generated photons from active layer remain inside LEDs by total internal reflection at the interface of semiconductor with air due to the high refractive index difference between LEDs epilayer (for GaN, n=2.5) and air (n=1). The light confining in LEDs will be reabsorbed by the metal electrode or active layer, reducing the efficacy of LEDs. Here, we present the first demonstration of enhanced light extraction by forming a MgO nano-pyramids structure on the surface of vertical-LEDs. The MgO nano-pyramids structure was successfully fabricated at room temperature using conventional electron-beam evaporation without any additional process. The nano-sized pyramids of MgO are formed on the surface during growth due to anisotropic characteristics between (111) and (200) plane of MgO. The ZnO layer with quarter-wavelength in thickness is inserted between GaN and MgO layers to increase the critical angle for total internal reflection, because the refractive index of ZnO (n=1.94) could be matched between GaN (n=2.5) and MgO (n=1.73). The MgO nano-pyramids structure and ZnO refractive-index modulation layer enhanced the light extraction efficiency ofV-LEDs with by 49%, comparing with the V-LEDs with a flat n-GaN surface. The angular-dependent emission intensity shows the enhanced light extraction through the side walls of V-LEDs as well as through the top surface of the n-GaN, because of the increase in critical angle for total internal reflection as well as light scattering at the MgO nano-pyramids surface.

• Applied Biological Chemistry
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• 제50권4호
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• pp.304-307
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• 2007

세포벽 분해 효소와 단백질 분해 효소를 이용하여 스피루리나 추출물을 효율적으로 생산할 수 있는 방법을 조사하였다. 세포벽 분해 효소인 Tunicase의 사용 농도는 2%가 적당하였다. 고형분 회수율과 핵산 관련 성분의 함량을 나타내는 spiruina extraction(SE) index를 기준으로 상업용 단백질 분해 효소를 선별하였다. 일곱 종류의 효소를 조사한 결과, Esperase가 가장 우수하였으며, 최적 사용량은 2%이었다. Tunicase와 Esperase를 순차전으로 반응시키거나 동시에 반응시켜도 고형분 회수율과 SE index는 매우 유사하였으며 동시에 사용하는 것이 반응 시간을 단축시킬 수 있었다. 두 효소를 동시에 반응시키면 단순 열수 추출보다 고형분 회수율은 약 45%$(45.2%{\rightarrow}65.3%)$, SE index는 약 75%$(11.4{\rightarrow}20.0)$ 증가하였다.

• 대한소아치과학회지
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• 제7권1호
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• pp.7-11
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• 1980

6877 children who visited to pedodontic department from 1976 to 1979, were surveyed on the state of dental caries, therapic inclination a year and yearly tendency of treatment. The results were as follows ; 1. The prevalence of dental caries tended to show the increase in general year by year. 2. Girls had higher d.e.f. T. & S. index and D.M.F. T. & S. index than boys generally. 3. Distribution of therapy a year. (1979) Amalgam Filling 4464 Pulpotomy 952 S.P.-Crown 1538 Gold Inlay 250 Space Maintainer 341 Extraction 1313 Orthodontic Appliance 206 4. Tendency of treatment in 1979 (compared with 1976) No. of new patients 87.5% increased Amalgam Filling 50.0% increased Extraction 31.4% increased Orthodontic Appliance 267.9% increased S.P.-Crown 225.8% increased Gold Inlay 27.8% decreased Space Maintainer 2.3% decreased Pulpotomy 20.5% decreased.

• Journal of Ginseng Research
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• 제15권3호
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• pp.192-196
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• 1991

As a part of studios on the Quality control of index components in crude drug preparations, extraction yields of ginseng saponins from crude drug extracts were identified by TLC and quantified by HPLC. So-Shi-Ho-Tang(小柴胡湯), Sa-Kun-Ja-Tang(四君子湯), Yook-Kun-Ja-Tang(六君子湯) and In-sam-Tang(人蔘湯) were extracted with water, 30%-ethanol, 50%-ethanol, 80%-ethanol and absolute ethanol to analyze ginseng saponins in the crude drug extracts prepared with various concentrations of ethanol. Ginseng saponins were extracted considerably more from the extracts with higher concentrations of ethanol than those with water or lower concentrations of ethanol. Extraction yields of ginseng-side-Rb$_1$, -Rb$_2$ and -R$_c$ from four crude drug preparations were the lowest as 4.9~45.9%, 5.0~40.1, and 6.3~43.7% in water extract and the highest as 29.5~62.6%, 26.7~61.4% and 31.4~62.0% in absolute ethanol extract, compared with those of 80%-methanol extracts.

• Toxicological Research
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• 제13권1_2호
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• pp.161-165
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• 1997

This study was conducted to investigate the skin irritation by transdermal administration of the three dyes. These dyes were originated from onion by using extraction method. By the order of extraction from onion, A-dye was obtained from onion by using water at 90-100$\circ$C. B-dye was extracted from A-dye with ethylacetate. After ethylacetate extraction from A-dye, the lower layer named as C-dye. Twenty-four New Zealand white rabbits were divided into three groups. The each groups was consisted of two subgroups according to high dose (extracted dyes) and low dose (the 100-fold dilutions of A-, Band C-dye). In primary skin irritation test of male New Zealand White rabbits, body temperature and weights were not significantly changed and blood cells were positioned in normal blood cell ranges of health rabbits. Primary irritation index was "0" in the test and control sites of all animals used in this study. By the results obtained in the present test, all dyes were evaluated as a non-irritant on the basis of the criteria of Draize.of Draize.