• 제목/요약/키워드: RAFT

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Technology, Market and Company Journeys: How Can We Help Them Succeed?

  • Malcolm, Parry
    • World Technopolis Review
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    • 제1권1호
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    • pp.27-41
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    • 2012
  • The science and technology park movement has been developing for over 60 years. The first developments simply relied on the co-location of tenant companies and the park's host to encourage technology transfer. This is in contrast with their modern counter parts which offer a range of active links between tenant companies and host organisations as well as a raft of business development services to support technology commercialisation. Many of these sites have also become important centres in regional innovation plans. In these cases they are supported by a range of local, regional and national policies that are aimed at establishing a business, technology and social environment which support innovation. The paper examines both the business development programmes developed by science and technology parks to support technology commercialisation and the macro conditions that are now being developed to support innovation.

Synthesis of an Ordered Porous SiCN Ceramic Film by Self-Assembly of Inorganic-Organic Diblock Copolymer

  • Nghiem Quoc Dat;Kim Dong-Pyo
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.296-296
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    • 2006
  • Highly temperature stable mesoporous materials have excellent properties and potential applications. Here we show a novel poly(vinyl)silazane-block-polystyrene diblock copolymer, which was synthesized by controlled/living free radical polymerization with reversible addition fragmentation chain transfer (RAFT) route. The obtained diblock copolymer occurs the phaseseparation on the nanoscale to form ordered nanostructure, which is converted to mesoprorous ceramic after heating at 800oC. This route demonstrates the preparation of highly temperature stable mesoporous silicon carbon nitrides (SiCN) ceramic film directed from highly cross-linking poly(vinyl)silazane blocks with high ceramic yield, which is different from previous pathway.

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Xanthate-Mediated Controlled Radical Polymerizations of N-Vinylcarbazole and Synthesis of Star Polymers

  • Mori, Hideharu;Ookuma, Hiroshi;Endo, Takeshi
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.322-322
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    • 2006
  • Well-defined poly(N-vinylcarbazole), poly(NVC), was synthesized by macromolecular design via interchange of the xanthate (MADIX)/reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of a suitable xanthate-type chain transfer agent (CTA). Good control of the polymerization was confirmed by the linear first-order kinetic plot, the molecular weight controlled by the monomer/CTA molar ratio, linear increase in the molecular weight with the conversion, and the ability to extend the chains by the second addition of the monomer. Star polymers having various architectures were also synthesized using this technique.

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Cholesterol, Statins, and Brain Function: A Hypothesis from a Molecular Perspective

  • Shin, Yeon-Kyun
    • Interdisciplinary Bio Central
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    • 제1권1호
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    • pp.2.1-2.3
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    • 2009
  • There is evidence that cholesterol in the brain plays an important role in the neurotransmitter release. A decrease of the cholesterol level severely hampers the activity of the membrane fusion machinery, thereby inhibiting the release. Meanwhile, the results from several clinical studies suggest that a low cholesterol level is linked to the dysfunction of some brain activities. Because the neurotransmitter release underlies the basic brain function, the combined results lead to a testable hypothesis that the cholesterol-lowering drugs may inhibit the neurotransmitter release at the synapse. Such inhibition of the release could result in impaired brain function for a limited group of people. A molecular basis for the hypothesis is discussed.

PANC-1세포에서 발현된 재조합 MT1-MMP의 효소 활성 (Activities of Recombinant MT1-MMP Expressed in PANC-1 Cells.)

  • 김혜난;정혜신
    • 생명과학회지
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    • 제18권3호
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    • pp.422-425
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    • 2008
  • Membrane-type 1 matrix metalloproteinase (MT1-MMP) is a membrane-associated zinc-dependent endoproteinase involved in extracellular matrix remodeling. MT1-MMP hydrolyzes ECM proteins like collagen and is involved in cancer cell migration and metastasis. Caveolins are integral membrane proteins and play a role in formation of caveolae, specialized membrane microdomains involved in clathrin-independent endocytosis. Recombinant MT1-MMP was transiently expressed in PANC-1 cells. Cells expressing recombinant MT1-MMP were able to hydrolyze collagen and migrate on collagen coated trans-well. Both subjacent collagen degradation and the cell migration conferred by recombinant MT1-MMP were inhibited by co-transfection of plasmids containing caveolin-1 cDNA. The results support that MT1-MMP is localized in lipid raft of the membrane and MT1-MMP activities in invasive cells could be inhibited by caveolin.

Epidermis Proliferative Effect of the Panax ginseng Ginsenoside $Rb_2$

  • Choi, Seong-Won
    • Archives of Pharmacal Research
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    • 제25권1호
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    • pp.71-76
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    • 2002
  • Ginseng has been used as a traditional medicine with various therapeutic effects. However, it is still unknown which component of this plant is effective at promoting wound healing. Recently, ginsenoside $Rb_2$ has been reported to improve wound healing. In this study, to investigate the reported wound healing effect of the ginsenoside $Rb_2$, cell morphology and protein factors involved in epidermal formation were evaluated by immunshemical and immunoblotting analysis. $Rb_2$ stimulated epidermal cell proliferation, and the cell showed a 1.5-fold increase in thymidine uptake compared to the control (p<0.05, n=3). Futheremore $Rb_2$, was found to stimulate epidermis formation in a dose-dependent manner in raft culture, and to dose dependently enhance the expressions of protein factors related to cell proliferation, namely, epidermal growth factor and its receptor, fibronectin and its receptor, keratin 5/14, and collagenase 1 (p<0.05, n=3~9). It is believed that ginsenoside $Rb_2$, enhances epidermal cell proliferation by upregulating the expressions of these proliferation-related factors.

A New Stationary Phase Prepared from Ground Silica Monolith Particles by Reversible Addition-Fragmentation Chain Transfer Polymerization

  • Lee, Seung-Mi;Zaidi, Shabi Abbas;Cheong, Won-Jo
    • Bulletin of the Korean Chemical Society
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    • 제31권10호
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    • pp.2943-2948
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    • 2010
  • Silica monolith powders were prepared by a new procedure where ground powders of proper size distribution were obtained without sieving. An initiator was attached to this ground monolith and polystyrene was bound by reversible addition-fragmentation chain transfer polymerization to give a new stationary phase. The separation efficiency of this phase was found better than that of the polystyrene bound phase based on conventional silica particles and that of the C18 bound silica monolith powders.

Brief description of the Design and Construction of the Burj Dubai Project, Dubai, UAE.

  • Abdelrazaq Ahmad K.
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
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    • pp.9-14
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    • 2005
  • The Burj Dubai Project will be the tallest structure ever built by man; when completed the tower will be more than 700 meter tall and more than 160 floors. The early integration of aerodynamic shaping and wind engineering considerations played a major role in the architectural massing and design of this residential tower, where mitigating and taming the dynamic wind effects was one of the most important design criteria. This paper presents a brief overview of the structural system development and considerations of the tower and discusses the construction planning of the key structural components of the tower.

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블록체인 네트워크의 대표노드 선출 및 해임에 관한 연구 (A Study on electing and dismissing delegate node of blockchain network)

  • 정필수;전우직;오형석;윤대일;강성원
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2019년도 추계학술발표대회
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    • pp.641-644
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    • 2019
  • 블록체인은 탈중앙화된 신뢰 기반 분산 데이터베이스로 높은 신뢰성과 보안성을 제공하지만 기존의 블록체인들은 확장성이 떨어진다는 문제를 지닌다. 이 문제를 해결하기 위해 기존의 방법들은 소수의 대표노드들을 선출하여 합의 과정을 간소화 하려 하였다. 그러나 이러한 시도는 대표 노드를 선출하기 위해 지분 기반 투표 방식을 사용하기 때문에 많은 지분을 가진 노드들에게 권한이 집중될 수 있다는 한계를 갖는다. 본 연구는 이러한 한계점을 해결한 대표노드 선출/해임 모델을 소개한다. 제안 방법은 Raft 의 투표 알고리즘을 확장하여 대표노드의 공정한 선출과 대표노드의 부적절한 행위를 예방한다. 제안 방법은 모델 검증을 통해 도달 가능성, 안전성, 활동성이 확인되었다.

Problems with a popular thick plate element and the development of an improved thick plate element

  • Cheng, Y.M.;Law, C.W.
    • Structural Engineering and Mechanics
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    • 제29권3호
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    • pp.327-349
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    • 2008
  • Some unreasonable results from the use of a popular thick plate element are discovered from the analysis of a raft foundation and a pile cap in Hong Kong. To overcome the problems, the authors have developed a new shear deformable beam which can be extended to a general quadrilateral shear deformable plate. The behaviour of this new element under several interesting cases is investigated, and it is demonstrated that the new element possesses very high accuracy under different depth/span ratios, and the results from this new element are good even for a coarse mesh.