• Journal of Ginseng Research
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• 제45권1호
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• pp.163-175
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• 2021

Background: Ginsenosides, which have strong biological activities, can be divided into polar or less-polar ginsenosides. Methods: This study evaluated the phytochemical diversity of the saponins in Panax ginseng (PG) root, American ginseng (AG) root, and Panax notoginseng (NG) root; the stem-leaves from Panax ginseng (SPG) root, American ginseng (SAG) root, and Panax notoginseng (SNG) root as well as the saponins obtained following heating and acidification [transformed Panax ginseng (TPG), transformed American ginseng (TAG), transformed Panax notoginseng (TNG), transformed stem-leaves from Panax ginseng (TSPG), transformed stem-leaves from American ginseng (TSAG), and transformed stem-leaves from Panax notoginseng (TSNG)]. The diversity was determined through the simultaneous quantification of the 16 major ginsenosides. Results: The content of ginsenosides in NG was found to be higher than those in AG and PG, and the content in SPG was greater than those in SNG and SAG. After transformation, the contents of polar ginsenosides in the raw saponins decreased, and contents of less-polar compounds increased. TNG had the highest levels of ginsenosides, which is consistent with the transformation of ginseng root. The contents of saponins in the stem-leaves were higher than those in the roots. The transformation rate of SNG was higher than those of the other samples, and the loss ratios of total ginsenosides from NG (6%) and SNG (4%) were the lowest among the tested materials. In addition to the conversion temperature, time, and pH, the crude protein content also affects the conversion to rare saponins. The proteins in Panax notoginseng allowed the highest conversion rate. Conclusion: Thus, the industrial preparation of less-polar ginsenosides from SNG is more efficient and cheaper.

• Journal of Ginseng Research
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• 제41권2호
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• pp.180-187
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• 2017

Background: The incidence of halitosis has a prevalence of 22-50% throughout the world and is generally caused by anaerobic oral microorganisms, such as Fusobacterium nucleatum, Clostridium perfringens, and Porphyromonas gingivalis. Previous investigations on the structure-activity relationships of ginsenosides have led to contrasting results. Particularly, the antibacterial activity of less polar ginsenosides against halitosis-related bacteria has not been reported. Methods: Crude saponins extracted from the Panax quinquefolius leaf-stem (AGS) were treated at $130^{\circ}C$ for 3 h to obtain heat-transformed saponins (HTS). Five ginsenoside-enriched fractions (HTS-1, HTS-2, HTS-3, HTS-4, and HTS-5) and less polar ginsenosides were separated by HP-20 resin absorption and HPLC, and the antimicrobial activity and mechanism were investigated. Results: HPLC with diode-array detection analysis revealed that heat treatment induced an extensive conversion of polar ginsenosides (-Rg1/Re, -Rc, -Rb2, and -Rd) to less polar compounds (-Rg2, -Rg3, -Rg6, -F4, -Rg5, and -Rk1). The antimicrobial assays showed that HTS, HTS-3, and HTS-4 were effective at inhibiting the growth of F. nucleatum, C. perfringens, and P. gingivalis. Ginsenosides-Rg5 showed the best antimicrobial activity against the three bacteria, with the lowest values of minimum inhibitory concentration and minimum bactericidal concentration. One major reason for this result is that less polar ginsenosides can more easily damage membrane integrity. Conclusion: The results indicated that the less polar ginsenoside-enriched fraction from heat transformation can be used as an antibacterial agent to control halitosis.

• 대한전자공학회논문지SP
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• 제39권2호
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• pp.1-10
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• 2002

이 논문에서는 크기와 영상 평면상에서 회전 (in-plane rotation) 변화를 가지는 정면 얼굴 영상의 인식성능을 향상시키기 위하여, 새로운 템플릿 (template) 기반 접근 방법들을 제안한다. 인식 성능을 향상시키기 위한 템플릿들은 크기와 회전 변화가 다른 다수의 영상들을 선형 또는 비선형 연산에 의하여 생성된다. 얼굴의 크기와 영상 평면에서 회전 변화에 무관한 얼굴의 특징을 추출하기 위하여 어파인 (affine) 변환, 로그폴라 (log-polar) 사상, 그리고 로그폴라 영상에 기반한 FFT들이 이용된다. 제안된 방법들은 인식률과 수행 시간 측면에서 비교된다. 실험 결과로부터 제안된 템플릿을 이용한 방법들의 인식률이 한 장의 영상으로 생성된 템플릿을 이용한 방법들의 인식률보다 우수함을 나타낸다. 어파인 변환을 이용한 방법의 인식률이 로그폴라 사상을 이용한 방법과 로그폴라 영상에 기반한 FFT 방법의 인식률보다 우수하며, 수행 시간 측면에서는 로그폴라 사상을 이용한 방법이 가장 빠르다.

• Natural Product Sciences
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• 제5권3호
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• pp.151-153
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• 1999

(+)-Hernandulcin is a sweet bisabolane-type sesquiterpene first isolated from Lippia dulcis Trev. (Verbenaceae). This oily compound is 1000-1500 times sweeter than sucrose but with poor solubility in water. Microbial transformation was employed to improve its water solubility, and a variety of microorganisms were screened for their ability to convert (+)-hernandulcin to more polar metabolites. Scale-up fermentation with Glomerella cinguiata, a fungal strain, has resulted in the isolation of a more polar metabolite (2).

• Ocean and Polar Research
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• 제24권3호
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• pp.289-300
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• 2002

The Lago Sofia conglomerates encased in the Cretaceous Cerro Toro Formation, southern Chile, represent a gigantic submarine channel system developed along a foredeep trough. The channel system consists of several tributaries along the trough margin and a trunk channel along the trough axis. Voluminous debris flows were generated ubiquitously along the tract of the submarine channel mainly by the failure of nearby channel banks or slopes. The flows transformed immediately into multiphase flows and resulted in very thick-bedded mass-flow deposits with a peculiar structure sequence. The mass-flow deposits commonly overlie fluted or grooved surfaces and consist of a lower division of clast-supported and imbricated pebble-cobble conglomerate with common basal inverse grading, and an upper division of clast- to matrix-supported and disorganized pebble conglomerate or pebbly mudstone with abundant intraformational clasts. The structure sequence suggests a temporal succession of a turbidity current, a bipartite hyperconcentrapted flow with active clast collisions near the flow base, and a cohesive debris flow probably with a rigid plug. The multiphase flow is interpreted to have resulted from transformation of clast-rich but cohesive debris flows. Cohesive debris flows appear to transform more easily into dilute flow types in subaqueous environments because they are apt to hydroplane. This is in contrast to the flow transitions in subaerial environments where noncohesive debris flows are dominant and difficult to hydroplane.

• KSBB Journal
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• 제4권1호
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• pp.8-10
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• 1989

불순응된 사질토에서 7,12 - 이메틸벤조안트라쎈 돌연변이 유발성의 불활성화에 대한 연구가 행해졌다. 토양에서 형성된 이메틸벤조아트라센의 극성이 강한 대사산물은 Ames분석에서 돌연변이성을 나타내지 않았다. 극성이 중간 또는 약한 대사산물은 돌연변이성을 보였으며, 그 변이비는 모체화합물의 변이비와 유사하였다.

• 한국세라믹학회지
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• 제51권3호
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• pp.218-223
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• 2014

The domain structures, dielectric properties, and phase transformation of (001)-oriented $Pb(Mg_{1/3}Nb_{2/3})O_3-x%PbTiO_3$ (PMN-x%PT) crystals for x=20, 30, 35, and 40 mole% have been investigated. PMN-20%PT consists of polar nano-domains (PND) which do not self-assemble into macro-domain plates. PMN-30%PT consists of PNDs which begin to self-assemble into colonies along preferred {110} planes. PMN-35PT consists of miniature polar domains on the nm scale. PMN-40%PT consists of {001} oriented lamella domains on the mm scale that have internal nano-scale heterogeneities. The dielectric properties of poled (001) PMN-x%PT single crystals have been measured for orientations both parallel and perpendicular to the [001] poling direction. The results of the temperature dependence of the dielectric constant and mesh scans for the 30%PT sample demonstrate that the initial monoclinic phase changes to single domain tetragonal phase and to cubic phase with increasing temperature.

• 항공우주기술
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• 제10권1호
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• pp.116-121
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• 2011

나로우주센터 추적레이더가 획득한 실시간 위치 정보는 발사통제시스템에서 위치, 속도, 비행궤도 표시, 예상궤도 진입여부 및 안전을 위한 비행종료시점 판단 등의 중요한 데이터로 사용된다. 추적레이더에서 발사통제시스템으로 전송하는 표적의 위치 정보는 추적레이더 중심의 좌표값 데이터이며, 발사통제시스템에서 추적레이더로 전송하는 Slaving 데이터는 발사대 중심의 좌표값 데이터이다. 이렇듯 추적레이더와 발사통제시스템 간의 송수신 데이터는 각 시스템에 맞게 적절하게 좌표 변환이 수행되어야 한다. 본 연구에서는 나로우주센터 추적레이더 간의 상호 데이터 송수신 및 발사통제시스템과의 데이터 통신에 사용되는 각각의 좌표계 및 좌표계 간의 좌표 변환에 대해 기술하였다.

• Communications for Statistical Applications and Methods
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• 제6권2호
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• pp.595-600
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• 1999

We present a simple geometric approach which uses polar transformation and elementary trigonometry to evaluating an orthant probability in a bivariate normal distribution. Figures are provided to illustrate the situation for varying correlation coefficient. We derive the distribution of the sample correlation coefficient from a bivariate normal distribution when the sample size is 2 as an application.

• 대한전자공학회논문지SP
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• 제39권1호
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• pp.61-69
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• 2002

능동 스테레오 비젼 시스템은 목표물 판별을 위해서 간단한 연산만으로 작은 시차값을 가지는 특징들만을 통과시킴으로써 목표물 위치 측정을 가능케 한다. 그런데 이 간단한 방법은, 복잡한 배경이 포함되거나 시차가 영인 영역에 다른 물체들도 동시에 존재하면 적용이 어렵게 된다. 이러한 문제점들을 해결하기 위하여, 본 논문에서는 시야 중심 영역의 해상도는 높이고 일반적으로 중요도가 낮은 주변의 해상도는 감소시키는 포비에이션 기법을 필터링 방법과 결합시켰다 포비에이트 영상 표현을 위하여 영상 피라미드 또는 로그폴라 변환을 사용하였다. 또한 추적이 수행되는 동안에 스테레오 시차가 작은 값이 유지되도록 투영을 이용하여 스테레오 시차를 추출하였다. 실험 결과는 로그폴라 변환이 복잡한 배경으로부터 목표물을 분리하는 제안된 방법이 영상 피라미드 또는 기존 방법보다 우수하며, 추적성능을 상당히 개선함을 보여주고 있다.