• Korean Chemical Engineering Research
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• 제58권2호
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• pp.273-279
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• 2020

본 연구에서는 바이오매스로부터 파클리탁셀 회수를 위한 전통적 용매 추출(conventional solvent extraction, CSE), 마이크로웨이브를 이용한 추출(microwave-assisted extraction, MAE), 초음파를 이용한 추출(ultrasound-assisted extraction, UAE) 방법을 비교하였다. 추출 용매 종류(아세톤, 클로로포름, 에탄올, 메탄올, 메틸렌 클로라이드)에 따른 영향을 조사한 결과, 메탄올이 모든 추출 방법에서 가장 적합하였다. 메탄올을 이용한 MAE와 UAE의 경우, 단 1회의 추출로 대부분의 파클리탁셀 회수(>95%)가 가능하였다. 또한 MAE와 UAE의 경우 추출 온도(25-45 ℃), 마이크로웨이브 파워(50-150 W), 초음파 파워(180-380 W)의 증가에 따라 파클리탁셀 회수율이 증가하였다. 또한 SEM 분석을 통해 바이오매스 표면을 조사한 결과, 표면 구조가 CSE의 경우에는 조금 주름진 형태를 보인 반면 MAE와 UAE의 경우에는 강한 충격으로 매우 거칠고 파괴된 형태를 보였다.

• 대한토목학회논문집
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• 제31권6D호
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• pp.849-856
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• 2011

본 연구에서는 교량의 구조계산서와 같이 여러 종류의 머리기호를 사용하며 제목의 계층구조가 복잡한 형식을 띄는 엔지니어링 문서의 비구조화된 텍스트 정보를 제목의 계층 구조에 따른 준구조화된 XML 문서로 변환시키는 방법을 제시한다. 텍스트 정보로부터 제목의 계층구조를 자동으로 추출하기 위해 문서구조분석 방법의 하나인 문서구조추출 기법을 이용하는 방법을 개발하였으며, 특히 개조식 구문의 식별방법을 개발하여 구조계산서 문서 계층구조의 제목추출과정 및 계층구분의 전체 정확도를 향상시킬 수 있는 방법을 제시하였다. 제시된 방법에 따른 응용모듈을 개발하였으며, 총 40개의 교량 구조계산서를 대상으로 그 성능을 평가하였다. 먼저, 20개의 강거더 상부 구조계산서를 대상으로 선행 연구결과와 비교하여 본 연구에서 개발된 응용모듈의 정확성과 신뢰도가 향상됨을 보였다. 또한, 다른 구조형식에 대한 구조계산서 20개에 대하여 개발된 모듈의 적용성을 평가하였다. 그 결과 본 연구에서 제안한 방법에 의한 문서 계층구조 분석의 최종 정확도는 평균 99% 수준 이상을 나타내고, 표준편차는 1.52로 나타나 본 연구에서 제시된 방법이 다양한 형식의 머리기호를 사용하여 제목을 구분하는 여러 엔지니어링 문서에도 적용이 가능함을 보였다.

• 펄프종이기술
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• 제40권2호
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• pp.65-72
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• 2008

This work evaluated the extractability of tobacco stem biomass for the papermaking type Reconstituted Tobacco Sheet(RTS). The effects of the soaking conditions on the hydration of stem biomass and the effects of the hydrated state on the mechanical extraction were investigated. In order to simulate the mechanical expression process of a papermaking type RTS mill, for example, the screw press process, the novel mechanical pressing analyzer was developed for this study. The hydration of stem biomass by soaking process was greatly affected by the soaking time and the soaking temperature. The longer soaking time and the higher soaking temperature resulted in the higher hydrated stem biomass. Since the higher hydrated stem had more combined water in the inner structure and resulted in the more flexible structure, the higher hydrated stem leaded to the more compressed filter cake and the higher water contents in the filter cake after the mechanical pressing. The pilot pulping experiments showed the difference in hydration and extractability between burley and bright tobacco stem. The bulkier structure of the burley stem resulted in the faster hydration by pilot pulping and leaded to the larger reduction in water soluble components. And the hydration process showed the major influence on the separation efficiency of water soluble components.

• Smart Structures and Systems
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• 제33권6호
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• pp.385-398
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• 2024

To improve the accuracy of time-frequency analysis (TFA) and instantaneous frequency (IF) extraction of structural dynamic response signals, this paper improves the spline-kernelled chirplet transform, and a new form of modified spline-kernelled chirplet transform (MSCT) based on revised Gaussian window function and energy concentration principle is put forward. The effectiveness of the proposed method is verified by numerical examples of single-component signal, multicomponent signal, single-degree-of-freedom Duffing nonlinear system and two-layer shear frame structure model. Then, a time-varying cable test is designed to collect the acceleration response signals under linear changing tension, and the IF extraction of these signals is performed by using MSCT, which further verifies the effectiveness and accuracy of this method. Through numerical simulation and experimental verification, it is proved that the proposed method can effectively extract the IF of nonlinear structure and time-varying structure.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3196-3202
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• 2012

Post-synthesis is used to synthesize organic hybrid inorganic mesoporous sieves. In this method, the activity and structure of the base sieve are crucial to obtain the definable hybrid materials. The chemical and physical properties of the base can be largely changed either by the final step of its synthesizing processes, by template removal which is accomplished with the oxidative thermal decomposition (burning) method or by solvent extraction method. In this paper we compared two methods for the post-synthesis of organic hybrid MCM-48. When the template was extracted with HCl/alcohol mixture, the final product showed larger pore size, larger pore volume and better crystallinity compared to the case of the thermal decomposition. The reactivity of the surface silanol group of template free MCM-48 was also checked with an alkylsilylation reagent $CH_2=CHSi(OC_2H_5)_3$. Raman and $^{29}Si$ NMR spectra of MCM-48 in the test reaction indicated that more of the organic group was grafted to the surface of the sample after the template was removed with the solvent extraction method. Direct synthesis of vinyl-MCM-48 was also investigated and its characteristics were compared with the case of post-synthesis. From the results, it was suggested that the structure and chemical reactivity can be maintained in the solvent extraction method and that organic grafting after the solvent extraction can be a good candidate to synthesize a definable hybrid porous material.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.409-412
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• 2006

Today's commercial high resolution satellite imagery such as IKONOS and QuickBird, offers the potential to extract useful spatial information for geographical database construction and GIS applications. Recognizing this potential use of high resolution satellite imagery, KARI is performing a project for developing Korea multipurpose satellite 3(KOMPSAT-3). Therefore, it is necessary to develop techniques for various GIS applications of KOMPSAT-3, using similar high resolution satellite imagery. As fundamental studies for this purpose, we focused on the extraction of 3D spatial information and the update of existing GIS data from QuickBird imagery. This paper examines the scheme for rectification of high resolution image, and suggests the convenient semi-automatic algorithm for extraction of 3D building information from a single image. The algorithm is based on triangular vector structure that consists of a building bottom point, its corresponding roof point and a shadow end point. The proposed method could increase the number of measurable building, and enhance the digitizing accuracy and the computation efficiency.

• Bulletin of the Korean Chemical Society
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• 제32권11호
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• pp.3855-3860
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• 2011

The competitive solvent extractions of alkali and alkaline earth metals by di-ionizable calix[4]arene nano-baskets were studied using nine conformers of calix[4]arene nano-baskets. The objective of this work is to assess the variation of macrocycle conformation, orientation and position of pendant moieties upon the extraction parameters (efficiency, selectivity and $pH_{1/2}$) of the complexes. The results revealed that alternation of ring conformation in calixarene scaffold affects the solvent extraction parameters towards alkali and alkaline earth metals, while changing the orientation of pendant moieties from ortho- to para- as well as cis- to trans-analogues depicted no changes in those extraction parameters.

• 마이크로전자및패키징학회지
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• 제18권4호
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• pp.91-95
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• 2011

GaN 기반의 LED에서 광 추출 효율을 정량적으로 분석하였다. Ray-Tracing기반의 시뮬레이션을 이용하여 사파이어 기판에 형성된 패턴의 형태, 크기, 깊이, 간격들을 분석하여 최적의 패턴 요소들을 도출하였다. 시뮬레이션의 결과로 최적의 패턴 형태는 반구 형태에서 높은 광 추출 효율을 보였다. 일반적인 패턴이 없는 사파이어 기판을 사용한 LED의 광 추출 효율보다 반구 형태의 패턴을 가진 사파이어 기판에서 약 40% 향상된 광 추출 효율을 보였다.

• 대한전자공학회논문지
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• 제18권2호
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• pp.36-43
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• 1981

본 논문은 한글 인식에 있어서 문제점으로 되어 있는 조합문자에서의 자소추출 방법의 제안에 관한 것이다. 한글의 구성원리에 입각하여 자소의 단치정보와 Stroke의 방향성을 고려하여 Top-down 적으로 한글의 구조를 분석하고, 이에 따른 3단계 처리에 의하여 자소가 순차적으로 추출되는 과정을 보였다. 일상 활동에서 사용되고 있는 문자중, 677자에 대한 자소의 추출실험결과, 96 %의 추출률을 얻어, 본 방식의 유효성을 확인할 수 있었다.

• Natural Product Sciences
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• 제28권2호
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• pp.89-92
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• 2022

In Asia, the roots of Paeonia lactiflora and Astragalus membranaceus have been used as therapeutic agents for thousands of years. Once the medicinal plants are harvested, they are dried and their ingredients are extracted by heat-mediated reflux extraction. However, the condensed structure of organic products (especially roots) limits the extraction of bioactive components. In this study, we assessed the effect of the puffing method (using high temperature and pressure) before the extraction process in relation to the profile and antioxidant capacity of active ingredients. We demonstrated that the additional puffing process before extraction methods improves the yield of polyphenol concentrations and antioxidant activities from the roots of P. lactiflora and A. membranaceus.