• Applied Biological Chemistry
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• v.50 no.3
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• pp.187-191
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• 2007

Comparative molecular similarity indice analysis (CoMSIA) models on the fungicidal activities of N-phenyl substituents (X) in N-phenyl-O-phenylthionocarbamate derivatives against rice sheath blight (Rhizoctonia solani: RS) and phytophthora blight (Phytophthora capsici: PC) were derived. Also, the characterizations of H-bonds between substrates and ${\beta}-tubulin$ were discussed quantitatively. It was revealed that, from the contour maps of CoMSIA models, the H-bond acceptor field contributed the most highly to fungicidal activity for two fungi in common. It is predicted that the selectivity in the fungicidal activity between two fungi is caused by results from the roles of H-bond donor disfavor functional groups in RS and H-bond acceptor disfavor functional groups in PC when these two groups induced at meta- and para-position on the N-phenyl ring. And also, if the substituents (X) are steric disfavor group, negative charge favor groups are introduced at the metaposition in RS and H-bond acceptor group is introduced at the para-position in PC, the antifungal activity against two fungi will be likely able to be increased.

• Proceedings of the Korean Vacuum Society Conference
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• 1994.06a
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• pp.54-69
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• 1994

메탄을 원료가스로 하여 ppECVD에 의해 다이아몬드성 탄소(DLC) 박막을 형성하였 으며 이 때 인가전력의 크기 및 주파수 그리고 보조가스의 종류가 opptical band gapp의 크 기에 미치는 영향에 대하여 연구하였다. DLC 박막의 opptical band gapp은 증착되는 이온의 에너지가 증가할수록 감소하였으며, 불활성 기체를 보조가스로 사용하는 경우 인가전력에 따른 opptical band gapp의 크기가 큰 폭으로 심화되었다. 수소를 보조가스로 사용한 경우는 높은 인가전력(100W)에서 opptical band gapp이 증가하는 것으로 밝혀졌으며 본 연구에서 새로이 제안된 증착기구의 모델에 의해 적절한 설명이 가능하였다.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.45 no.4
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• pp.34-40
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• 2008

This paper presents a vision based walking robot control system using hand shape recognition. To recognize hand shapes, the accurate hand boundary needs to be tracked in image obtained from moving camera. For this, we use an active contour model-based tracking approach with mean shift which reduces dependency of the active contour model to location of initial curve. The proposed system is composed of four modules: a hand detector, a hand tracker, a hand shape recognizer and a robot controller. The hand detector detects a skin color region, which has a specific shape, as hand in an image. Then, the hand tracking is performed using an active contour model with mean shift. Thereafter the hand shape recognition is performed using Hue moments. To assess the validity of the proposed system we tested the proposed system to a walking robot, RCB-1. The experimental results show the effectiveness of the proposed system.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.4
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• pp.271-276
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• 2009

The 3-dimensional quantitative structure-activity relationships (3D-QSARs) models between the substituents with changing groups ($R_1$ & $R_2$) of 4-($R_1$)-benzyl alcohol and 4-($R_2$)-phenol derivatives as substrate molecule and their inhibitory activities against tyrosinase were derived and discussed quantitatively. The optimized CoMSIA 2 model have best predictability and fitness ($r^2\;=\;0.858$ & $q^2\;=\;0.951$). The contour maps of optimized CoMSIA 2 model showed that, the inhibitory activities of the analogues against tyrosinase were expected to increase when hydrophobic favor, negative charge favor, steric disfavor and hydrogen bond donor disfavor groups were substituted at the $R^2$ position. When the positive charge and the hydrogen bond donor favor groups were substituted at the $R_1$ position, it is predicted that the substituents will be able to increase the inhibitory activity. However, hydrogen bond acceptor did not affect inhibitory activities of tyrosinase.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.238-242
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• 2006

The herbicidal activities against the pre-emergence of rice plant (Oryza sativa L.) and barnyard grass (Echinochloa crus-gall) with changing substituents $(R_1-R_4)$ of new 5-benzofuryl-2-[1-(alkoxyimino) alkyl]-3-hydroxycyclohex-2-en-1-one derivatives as substrate molecules were studied quantitatively using comparative molecular field analyses (CoMFA). The optimized CoMFA models (rice plant: A5 & barnyard grass: B3) were derived from atom based fit alignment and a combination of CoMFA fields. The two models for herbicidal activity against two plants showed the best predictability and fitness ($q^2$>0.6 & ${r^2}_{ncv.}$>0.94) for the herbicidal activities. Also, CoMFA-HINT contour maps showed that the selective herbicidal activity between rice plant and barnyard grass depends on the hydrophobicity of $R_2\;and\;R_3$ groups in molecule. Therefore, it is expected that the herbicidal activity against barnyard grass will be improved by the introduction of the steric bulk small and hydrophobic group.

• Korean Chemical Engineering Research
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• v.47 no.3
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• pp.373-379
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• 2009

Cesium carbonate was used as an adsorbent to capture carbon dioxide from gaseous stream of carbon dioxide, nitrogen, and moisture in a fixed-bed to obtain the breakthrough data of $CO_2$. The deactivation model in the non-catalytic heterogeneous reaction systems is used to analyze the sorption kinetics among carbon dioxide, carbonate, and moisture using the experimental breakthrough data. The experimental breakthrough data are fitted very well to the deactivation model than the adsorption isotherm models in the literature.

• Journal of Energy Engineering
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• v.23 no.1
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• pp.58-66
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• 2014

Catalytic gasification of a low rank coal- Inner Mongolian lignite has been carried out with carbon dioxide. The gasification reactions were performed in a thermogravimetric analyzer at temperatures of $600^{\circ}C$ to $900^{\circ}C$. The kinetic parameters were evaluated using three different gas-solids reaction models and the prediction ability of each model were compared. Among the models evaluated, the modified volumetric model was found to correlate best both the non-catalytic and catalytic gasification reactions. The theoretical models, homogeneous and shrinking-core models, were found to satisfactorily correlate gasification reactions for the non-catalytic and $FeSO_4$-catalyzed reactions. In case of alkali metal catalysts, the catalytic activity was mostly pronounced at a low temperature of $600^{\circ}C$ and observed to decrease by 50% as the temperature was increased to $700^{\circ}C$, and it remained nearly constant at temperature over $800^{\circ}C$. The order of catalytic activity was found to be: $K_2CO_3$ > $Na_2CO_3$ > $K_2SO_4$ > $FeSO_4$.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1964-1965
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• 2011

본 연구에서는 패턴분류를 위해 기존의 방사형 기저 함수 신경회로망(Radial Basis Funtion Neural Network)과 다항식 신경회로망(Polynomial Neural Network)을 결합한 다중 출력 방사형 기저 함수다항식 신경회로망 (Multi Output Radial Basis Funtion Polynomial Neural Network)의 분류기를 제안한다. 제안된 모델은 PNN을 기본 구조로 하여 1층에 기존의 다항식 노드 대신 다중 출력 형태의 RBFNN을 적용 한다. RBFNN의 은닉층에는 기존의 활성함수가 아닌 fuzzy 클러스터링을 사용하여 입력 데이터의 특성을 고려한 적합도를 사용하였다. PNN은 입력변수의 수와 다항식 차수가 모델의 성능을 결정함으로 최적화가 필요하며 본 논문에서는 Differential Evolution(DE)을 사용하여 모델의 구조 및 파라미터를 최적화시켜 모델의 성능을 향상시켰다. 패턴분류기로써의 제안된 모델을 평가하기 위해 pima 데이터를 이용하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.225-225
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• 2012

국내에서 크라이오펌프를 생산한 지 여러해가 지나 냉동기 및 활성탄 어레이를 비롯한 대부분의 핵심 부품들을 가공하고 펌프를 조립하는 것을 자체적으로 해결하고 있지만 지금까지 펌프의 구조설계는 외국 제휴 회사에서 전수받은 것을 큰 수정없이 고수해 온 것이 현실이다. 따라서 펌프의 성능에 관한 별도의 시험과정 없이도 제공받은 성능값을 그대로 제시하는 것으로 충분했다. GVT(주)는 국내의 선도적인 크라이오펌프 전문생산 업체로서 독자적인 냉동기와 어레이 및 배플 설계에 기초한 신규 모델들을 정립하고 펌프를 생산하기 시작하였으며 다양한 크기의 표준용기를 마련하여 전 모델에 대해서 엄격한 시험검사를 시행하고 있다. 본 발표에서는 특별히 구경 200 mm UHV형 크라이오 펌프의 배기속도, 배기용량, cross-over 등 주요 배기성능 지표들을 측정한 결과 및 몬테카를로 계산을 통한 예측치와 비교한 결과를 소개한다.

• Journal of the Institute of Convergence Signal Processing
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• v.1 no.2
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• pp.122-130
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• 2000

This paper mainly deals with the modified version of conventional PRMA(Packet Reservation Multiple Access). In the existing PRMA schemes, the occupied slot in the initial access state is not allowed to be reserved in the silent period and retrial of gaining the slot access has to pay additional packet dropping. Whereas in the modified model, we propose to utilize a control minislot that maintains slot reservation and this prevents additional packet drop occurrence since initial access, and this slightly improves the system performance.