• 제어로봇시스템학회논문지
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• 제17권9호
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• pp.857-862
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• 2011

This paper studies the output consensus problem for a class of heterogeneous linear multi-agent systems under a fixed directed communication network. The dynamics, as well as its dimension, of each agent can widely differ from the others, but all the agents are assumed to have the same transfer matrix. In addition, only the system outputs are constrained to be delivered through the network. Under these conditions, we show that the output consensus is reached by a group of identical controllers, which is designed to achieve the state consensus for the homogeneous multi-agent system obtained from the minimal realization of the transfer matrix. Finally, an example is given to demonstrate the proposed result.

• KSBB Journal
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• 제8권2호
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• pp.110-114
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• 1993

Vinblastine, an anticancer agent was produced by chemical coupling of two different monomeric indole alkaloids, vinblastine and catharanthine in the presence of ferric ion. Vindoline was efficiently extracted from the leaves of vinca (Cafharanthus roseus) by using supercritical carbon dioxide, whereas catharanthine was chemically extracted from the in vitro cultured hairy roots. The extracted crude monomeric precursors were purified by a two-step preparative TLC. The coupling reaction was carried out in the 0.1M glycine buffer(pH 2.0, 5ml) containing 40mM FeC13 with purified vindoline(0.3mg) and catharanthine(0.3mg) at 4$^{\circ}C$. The production yields (weight %) of vinblastine and 3', 4'-anhy-drovinblastine in the products were 23.2 and 26.0, respectively. The produced vinblastine was confirmed by FAB-MS.

• Macromolecular Research
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• 제10권1호
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• pp.24-33
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• 2002

Interfacial and microfailure properties of carbon fiber/epoxy composites were evaluated using both tensile fragmentation and compressive Broutman tests. A monomeric and two polymeric coupling agents were applied via the electrodeposition (ED) and the dipping applications. A monomeric and a polymeric coupling agent showed significant and comparable improvements in interfacial shear strength (IFSS) compared to the untreated case under both tensile and compressive tests. Typical microfailure modes including cone-shaped fiber break, matrix cracking, and partial interlayer failure were observed under tension, whereas the diagonal slipped failure at both ends of the fractured fiber appeared under compression. Adsorption and shear displacement mechanisms at the interface were described in terms of electrical attraction and primary and secondary bonding forces.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2012년도 추계학술대회 논문집
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• pp.785-786
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• 2012

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2012년도 춘계학술대회 논문집
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• pp.475-476
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• 2012

• 공업화학
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• 제29권1호
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• pp.37-42
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• 2018

폴리프로필렌(PP)과 케나프섬유(KF) 펠트의 상용성 개선을 위해 3종류의 실란 커플링제 1 wt%를 PP/KF 펠트에 처리하여 PP/KF와 PP/KF/폴리우레탄(PU) 펠트 복합체를 제조하였다. KF에 실란 커플링제 결합여부 확인을 위해 Si-O-Si와 Si-O-C 작용기를 적외선분광기(FT-IR)와 X선 광전자분광분석기(XPS)를 이용하여 측정하였다. 열적 특성분석을 위해 시차주사열용량분석기와 열중량분석기를 이용하였으며, 실란 커플링제가 처리된 PP/KF 복합체의 열안정성이 증가하는 결과를 보여주었다. PP/KF와 PP/KF/PU 복합체의 인장, 굴곡 그리고 충격특성을 분석한 결과 기계적 특성의 개선효과는 (3-Aminopropyl)triethoxysilane (APS) 1-2 wt%에서 가장 우수하였다. 이와 같은 기계적물성의 개선은 실란 작용기가 천연섬유와 결합하여 PP와 KF의 상용성을 향상시킨 결과로 해석할 수 있고, 인장시험 후 파단면의 SEM 결과를 통해 확인하였다.

• 한국정보처리학회논문지
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• 제6권12호
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• pp.3548-3558
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• 1999

여러 종류의 기존의 다중 에이전트 프레임웍들(multi-agent frameworks)이 에이전트의 지적인 능력의 표현을 위하여 고수준의 지식 표현 언어를 지원한다. 하지만 그들의 에이전트 프로그래밍 인터페이스는 지식 표현 언어 뿐 아니라 어떤 다른 범용의 프로그래밍 언어들의 사용을 요구한다. 일반적으로 고수준 지식 표현 언어와 범용의 프로그래밍 언어간에는 언어의 수준 및 자료 표현 모델에 있어서 상당한 차이가 있으며, 그런 차이는 지능형 에이전트의 개발에 필요한 요소들의 결합에 관련된 문제점들을 발생시킨다. 본 논문은 그런 문제점들의 극복을 위해 개발한 새로운 유형의 지능형 에이전트 쉘 INAS(INtelligent Agent Shell) 버전 2에 대한 것이다. 지능형 에이전트의 개발을 위하여 고수준의 지식 표현 언어와 범용 프로그래밍 언어를 결합하여 사용해야 하는 기존의 에이전트 프레임웍들과 달리 INAS 버전 2는 그 자체만으로 에이전트들을 구축할 수 있는 고수준의 통합 에이전트 구축 언어를 지원한다. 따라서 INAS 버전 2를 사용한 지능형 에이전트의 개발은 지능형 에이전트의 개발에 필요한 요소들의 결합에 관련된 기존의 에이전트 프레임웍들의 문제점들을 겪지 않는다. 몇 종류의 지능형 에이전트들의 개발을 통하여 INAS 버전 2의 통합 에이전트 구축 언어가 지능형 에이전트들의 개발에 효과적 임을 경험할 수 있었다.

• Restorative Dentistry and Endodontics
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• 제22권1호
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• pp.144-155
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• 1997

This study evaluated shear bond strength between porcelain and resin cement according to various surface treatments of porcelain, and surface condition of debonded porcelain. 50 porcelain specimens(Celay block A2M7) and composite resin specimens(Clearfil Photo-Bright) were prepared, and divided into 5 experimental groups according to the treatment method of porcelain surface. 5 experimental groups by surface treatments were as follows; CONTROL Group : No surface treatment was done on the surface of porcelains. SAND Group : The surface of porcelains were sandblasted with $50{\mu}m$ aluminum oxide for 5 seconds. HF Group: The surface of porcelains were etched with 8% Hydrofluoric acid for 4 minutes. SIL Group: The surface of porcelains were coated with silane coupling agent and heated at $100^{\circ}C$ for 5 minutes. SAND+HF+SIL Group : The surface of porcelains were sandblasted with $50{\mu}m$ aluminum oxide for 5 seconds and etched with 8% Hydrofluoric acid for 4 minutes, and coated with silane coupling agent and heated at $100^{\circ}C$ for 5 minutes. After surface treatments on the prepared porcelain surface two pastes of Panavia 21$^{(R)}$ were mixed, they were applied between composite resin block and porcelain surface, and then excessive resin cements were removed, and its margin was surrounded with Oxyguard II. All specimens were stored for 24 hours in water at $37^{\circ}C$ and tested with Instron testing machine between porcelains and resin cements, and debonded porcelain surfaces were observed under Scanning Electon Microscope(Hitachi S-2300) at 20kvp. The values from each group were compared statistically by Student's t-test. The obtained results were as follows; 1. The shear bond strength without surface treatment of porcelain was the lowest among all experimental groups(p<0.05). 2. The detached porcelain surface with sandblasting alone had more remarkable cracks than with only Hydrofluoric Acid or Silane coupling 2gent, but showed the lowest value of shear bond strength among surface treated groups(p<0.05), 3. When porcelain surface was treated by hydrofluoric acid, it affected shear bond strength more than silane coupling agent, but there were no significant statistical differences(p>0.05). 4. When three methods were combined to increase shear bond strength between porcelains and resin cements, its value was the highest than the others(p<0.05). 5. In Scannig Electron Micrograph of detached porcelain surface with no treatment, the sample revealed adhesive failure between the porcelain and resin cement whereas detached porcelain surface with combination of three method cohesive failure on the porcelain.

• Carbon letters
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• 제7권2호
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• pp.87-96
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• 2006

This paper describes the physical properties of filled Nylon6 composites resin with nano-sized carbon black particle and graphite nanofibers prepared by melt extrusion method. In improving adhesions between resin and fillers, the surface of the carbon filler materials were chemically modified by thermo-oxidative treatments and followed by treatments of silane coupling agent. Crystallization temperature and rate of crystallization increased with increases in filler concentration which would act as nuclei for crystallization. The silane treatments on the filler materials showed effect of reduction in crystallization temperature, possibly from enhancement in wetting property of the surface of the filler materials. Percolation transition phenomenon at which the volume resistivity was sharply decreased was observed above 9 wt% of carbon black and above 6 wt% of graphite nanofiber. The graphite nanofibers contributed to more effectively in an increase in electrical conductivity than carbon black did, on the other hand, the silane coupling agent negatively affected to the electrical conductivity due to the insulating property of the silane. Positive temperature coefficient (PTC) phenomenon, was observed as usual in other composites, that is, temperature increase results conductivity increase. The dispersity of the fillers were excellently approached by melt extrusion of co-rotational twin screw type and it could be illustrated by X-ray diffraction and SEM.

• Journal of the Korean Wood Science and Technology
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• 제34권5호
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• pp.59-66
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• 2006

The thermal properties of wood flour, Hwangto, and maleated polyethylene (MAPE) reinforced HDPE composites were investigated in this study. The thermal behavior of reinforced wood polymer composites was characterized by means of thermogravimetric (TGA) and differential scanning calorimetric (DSC) analyses. Hwangto and MAPE were used as an inorganic filler and a coupling agent, respectively. According to TGA analysis, the increase of wood flour level increased the thermal degradation of composites in the early stage, but decreased in the late stage. On the other hand, Hwangto reinforced composites showed the higher thermal stability than virgin HDPE, from the determination of differential peak temperature ($DT_p$). Decomposition temperature of wood flour and/or Hwangto reinforced composites increased with increase of heating rate. From DSC analysis, melting temperature of reinforced composites little bit increased with the addition of wood flour or Hwangto. As the loading of wood flour or Hwangto to HDPE increased, overall enthalpy decreased. It showed that wood flour and Hwangto absorbed more heat energy for melting the reinforced composites. Hwangto reinforced composites required more heat energy than wood flour reinforced composites and virgin HDPE. Coupling agent gave no significant effect on the thermal properties of composites. Thermal analyses indicate that composites with Hwangto are more thermally stable than those without Hwangto.