• 생약학회지
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• 제23권2호
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• pp.115-116
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• 1992

From the bulbs of Erythronium japonicum Decaisne(Liliaceae), ${\beta}-sitosterol$ and its $3-O-{\beta}-D-glucoside$ together with fatty acids were isolated. All compounds were identified on the basis of spectral data. Campesterol and stigmasterol were also identified as minor components. Paimitic acid was identified as a major component and stearic, oleic, arachidic, behenic, tricosanoic and lignoceric acids were also characterized as minor ones.

• Steel and Composite Structures
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• 제20권3호
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• pp.469-486
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• 2016

Codes EN 1993 and EN 1994 require to take into account actual joint characteristics in the global analysis. In order to implement the semi-rigid connection effects in frame design, knowledge of joint rotation characteristics ($M-{\phi}$ relationship), or at least three basic joint properties, namely the moment resistance $M_R$, the rotational stiffness $S_j$ and rotation capacity, is required. To avoid expensive experimental tests many methods for predicting joint parameters were developed. The paper presents a comprehensive analytical model that has been developed for predicting the moment resistance $M_R$, initial stiffness $S_{j.ini}$ and rotation capacity of the minor axis, composite, semi-rigid joint. This model is based on so-called component method included in EN 1993 and EN 1994. Comparison with experimental test results shows that a quite good agreement was achieved. A computer program POWZ containing proposed procedure were created. Based on the numerical simulation made with the use of this program and applying regression analysis, simplified equations for main joint properties were also developed.

• 한국수소및신에너지학회논문집
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• 제8권1호
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• pp.43-47
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• 1997

A new type of anode materials in form of nanocrystalline composite powders has been developed that offers the potential for dramatically improved discharge capacity and initial activation rate. The composites are synthesized by ball milling of two components - a major component (basic component) having high hydrogen capacity and a minor component (surface activator) with good electrocatalytic activity. The capacity increase observed by ball milling with surface activator. The ball-milled composite materials are easier to activate than the non ball-milled basic component.

• Bulletin of the Korean Chemical Society
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• 제24권9호
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• pp.1345-1350
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• 2003

Principal component analysis based two-dimensional (PCA-2D) correlation analysis is applied to FTIR spectra of polystyrene/methyl ethyl ketone/toluene solution mixture during the solvent evaporation. Substantial amount of artificial noise were added to the experimental data to demonstrate the practical noise-suppressing benefit of PCA-2D technique. 2D correlation analysis of the reconstructed data matrix from PCA loading vectors and scores successfully extracted only the most important features of synchronicity and asynchronicity without interference from noise or insignificant minor components. 2D correlation spectra constructed with only one principal component yield strictly synchronous response with no discernible a asynchronous features, while those involving at least two or more principal components generated meaningful asynchronous 2D correlation spectra. Deliberate manipulation of the rank of the reconstructed data matrix, by choosing the appropriate number and type of PCs, yields potentially more refined 2D correlation spectra.

• Journal of Plant Biology
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• 제27권1호
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• pp.33-41
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• 1984

The relationships and character variations on 5 taxa of Calystegia were examined by sluster analysis and principal component analysis. Thirteen Calystegia population samples from the middle part of Korea were observed. Although minor differences were noted, essentially similar results were obtained from the phenograms by UPGMA, UPGMC and Ward's clustering methods, and these results were in accordance with those obtained from the ordination plots by principal component analysis. C. soldanella is distantly connected with the other taxa mainly because of its morphologically different leaf organs. Based on the difference on the first principal component, C. hederacae is kept apart from the rest 3 taxa. In the relationships among C. japonica, C. sepium var. americana and C. davurica, mivor differences were obtained from the 3 clustering methods. As to the character variations among different populations within a taxon, they are slight in C. soldanella and C. sepium var. americana, but remarkable in C. hederacae and C. davurica.

• 전자공학회논문지C
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• 제35C권6호
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• pp.88-98
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• 1998

부분공간 인식기는 Karhunen-Loeve (KL) 변환을 기반으로 하는 대표적인 패턴인식 방법이다. 이 부분 공간 인식기는 고차원의 패턴을 저차원의 부분공간에 나타내어 인식을 한다. 그러나 차원 감축으로 인한 정보의 손실로 principal components가 유사하게 나타나는 패턴간에는 분별이 어려워지는 단점이 있다. 본 논문에서는 이러한 부분공간 인식기의 단점을 해결하기 위해 일반적으로 무시되는 minor components로 표현되는 패턴의 노벨티 성분을 이용하는 결합된 다중 노벨티 신경망 인식기를 제안하고 부분공간 인식기와 결합을 통해 인식률을 제고하는 방법을 제시한다. 필기체 숫자 데이터베이스에 대해서 제안한 인식기를 구성하고 특성을 분석한다. 제안한 방법은 다른 인식기들에 비해서 신경망에 사용된 가중치의 수는 증가하지만 가장 우수한 인식 성능을 나타내었다.

• 식물분류학회지
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• 제42권2호
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• pp.126-140
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• 2012

국내에 분포하는 나자스말속(Najas L.) 분류군의 형태적 변이를 파악하고 각 분류군의 식별형질을 검토하기 위하여 32개 정량형질을 이용하여 주성분분석을 수행하였다. 나자스말속의 분류군에서 잎의 너비, 엽초의 모양, 엽연의 거치수, 약실의 수, 한 줄에 배열하는 종자의 그물눈 수와 길이의 비 등이 유용한 식별형질로 파악되었다. 자웅이주인 민나자스말(N. marina)은 잎과 줄기, 수꽃과 암꽃, 열매가 대형으로서 자웅동주인 다른 분류군들과 뚜렷하게 구분되었다. 자웅동주인 분류군들 중에서 나자스말(N. graminea), 실나자스말(N. gracillima), 동아나자스말(N. orientalis)은 영양 형질에 의하여 식별이 가능하지만, 톱니나자스말(N. minor)과 큰톱니나자스말(N. oguraensis)은 수꽃에 있는 약실의 수에 의해서만 구분되었다.

• 한국응용곤충학회지
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• 제53권3호
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• pp.239-246
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• 2014

같은 속의 복숭아순나방(Grapholita molesta)과 복숭아순나방붙이(G. dimorpha)는 기주범위와 야외에서의 성충 발생 양상이 유사하다. 또한 두 종은 성페로몬 성분으로 cis-8-dodecenyl acetate (Z8-12:Ac)와 trans-8-dodenceyl acetate (E8-12:Ac)을 공통으로 사용하고 있는데, 이 두 성분으로 구성된 상용 성페로몬 유인제에 두 종이 혼합되어 유인된다. 본 연구는 복숭아순나방붙이 트랩에 복숭아순나방이 혼합유인되는 현상을 줄이기 위해 성페로몬 미량성분의 효과를 분석했다. 복숭아순나방붙이 성페로몬인 Z8-12:Ac/E8-12:Ac = 85/15에 cis-8-tetradecenyl acetate(Z8-14:Ac)를 첨가했을 때, 복숭아순나방붙이의 유인은 유지되면서 복숭아순나방의 유인은 유의하게 억제되었다. Dodecyl acetate (12:Ac)와 tetradecyl acetate (14:Ac)의 첨가는 두 종의 유인력에 영향을 주지 않았다. 한편 Z8-12:Ac/E8-12:Ac/Z8-14:Ac = 85/15/10의 세 성분 성페로몬에 trans-8-tetradecenyl acetate (E8-14:Ac)를 첨가했을 때, 복숭아순나방붙이의 유인이 오히려 유의하게 억제되었다. 이상의 결과로부터 Z8-12:Ac/E8-12:Ac/Z8-14:Ac = 85/15/10의 조성이 개선된 복숭아순나방붙이의 성페로몬으로 제시되었다.

• Bulletin of the Korean Chemical Society
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• 제16권12호
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• pp.1184-1189
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• 1995

The rapid quenching dynamics of F center excitation by OH- defects in KCl crystals are investigated by monitoring ground state absorption bleach recovery, using a picosecond streak camera absorption spectrometer. F center absorption bleach in OH--doped crystals shows three distinguishable recovery components with the current temporal resolution, designated as slow, medium and fast components. The slow one is due to the normal relaxation process of F* centers as found in OH--free crystals. The others are consequent on energy transfer from electronically excited F centers to OH--vibrational levels. The fast component is a minor energy transfer process and resulting from the relaxation of somewhat distant, not the closest, associated pairs of F* and OH- defects. The energy transfer between widely separated F* and OH- defects opens up a recovery process via the medium component which is assisted by OH- librations, lattice vibrations and OH- dipole reorientations. The quenching behaviors of F* luminescence and photoionization by OH- are explained well by the relaxation process of the medium component.

• Structural Engineering and Mechanics
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• 제54권2호
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• pp.379-392
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• 2015

A number of acceleration-based damage detection methods have been developed but they have not been widely applied in engineering practices because the acceleration response is insensitive to minor damage of civil structures. In this article, a damage detection approach using the long-gauge strain sensing technology and the principle component analysis technology is proposed. The Long gauge FBG sensor has its special merit for damage detection by measuring the averaged strain over a long-gauge length, and it can be connected each other to make a distributed sensor network for monitoring the large-scale civil infrastructure. A new damage index is defined by performing the principle component analyses of the long-gauge strains measured from the intact and damaged structures respectively. Advantages of the long gauge sensing and the principle component analysis technologies guarantee the effectiveness for structural damage localization. Examples of a simple supported beam and a steel stringer bridge have been investigated to illustrate the successful applications of the proposed method for structural damage detection.