• Bulletin of the Korean Chemical Society
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• 제19권10호
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• pp.1047-1054
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• 1998

We present the results of molecular dynamics simulations for three different systems of bilayers of long-chain alkyl thiol [S(CH2)15CH3] molecules on an solid-solid interface using the extended collapsed atom model for the chain-molecule. It is found that there exist two possible transitions: a continuous transition characterized by a change in molecular interaction between sites of different chain molecules with increasing area per molecule and a sudden transition from an ordered lattice-like state to a liquid-like state due to the lack of interactions between sites of chain molecules on different surfaces with increasing distance between two solid surfaces. The third system displays a smooth change in probability distribution characterized by the increment of gauche structure in the near-tail part of the chain with increasing area per molecule. The analyses of energetic results and chain conformation results demonstrate the characteristic change of chain structure of each system.

• 대한전자공학회논문지TC
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• 제45권12호
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• pp.74-82
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• 2008

본 논문에서는 다중 체인구조를 이용한 P2P 기반 IPTV 시스템을 제안한다. 제안하는 시스템은 P2P 네트워크의 특징인 peer의 빈번한 가입과 탈퇴 상황에서 단순한 과정으로 네트워크를 재구성하는 장점이 있다. 인터넷과는 달리 ISP가 관리하는 IPTV 환경은 전송회선의 속도와 안정성이 일정수준으로 보장되어 있다. 따라서 IPTV 환경에서의 P2P 네트워크는 단순성 측면을 우선적으로 고려해야 한다. 기존에 제안되어있는 단일 체인구조는 단순성을 강조하였으나 같은 채널을 시청하는 peer의 개수가 증가하면 체인의 끝 부분에 연결되어 있는 peer는 상당한 delay가 발생한다. 제안하는 시스템은 이러한 delay 문제를 해결하기 위하여 체인을 여러 개의 레벨로 분리하고 각 레벨은 다시 span으로 나누었다. 레벨과 span으로 분리를 하였지만 기본적인 구조는 체인구조이므로 peer가 join 하거나 departure 할 경우에 단순한 네트워크의 재구성 과정을 제공한다. 수치적인 해석을 통해 본 논문에서 제안한 다중 체인구조를 이용한 P2P 시스템이 단일 체인구조 방식에 비해 delay 및 신뢰도 성능이 우수하다는 것을 보여준다.

• 기술혁신연구
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• 제15권1호
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• pp.203-233
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• 2007

This study investigates how characteristics in the value-chain industrial cluster affect the R&D investment and the output of firms in each industries. For this, we try to extract the inter-industrial networking structure from the input-output table in which 17 manufacturing sectors are included. In particular, we will give shape to the "unit structure" which shows the intermediary flows of goods and services between industries in order to get an unit of final demand in a certain industry. Using this "unit structure", we can try the inter-industrial networking analysis and get some indices of centrality and centralization related to the characteristics of each industries in the value-chain industrial cluster. The results show that the centrality in the value-chain industrial cluster does not have any consequence for the R&D investment and the output in each industries. However, there is a correlation between the centralization in the value-chain industrial cluster and the R&D investment and the output of firms in each industries. These results may be very suggestive in bringing up a new frame of industrial cluster policy in a macro level.

• 경영과정보연구
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• 제27권
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• pp.149-172
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• 2008

Since the 9/11 terror attack, the event which caused supply chain disruption, supply chain security has becomes more important than ever before. Furthermore, such company's logistics strategies conflicting supply chain security as increased global sourcing, JIT manufacturing are increasing supply chain vulnerability. It could burden for global companies to strengthen supply chain security because not only it requires additional investment cost but also changes of companiy's global logistics strategy. However, on the other hand, supply chain visibility and resilience can be improved through supply chain security. In addition, it allows companies to stabilize supply chain structure as well as rapid and flexible response to market demand. The key issue is balancing between efficiency and supply chain security. To do this, identifying risk elements under the supply chain and assessing vulnerability of each supply chain components should be performed before developing efficient supply chain security management system without obstructing supply chain efficiency.

• Fisheries and Aquatic Sciences
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• 제9권1호
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• pp.22-29
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• 2006

We determined the partial cDNA of Type II procollagen ${\alpha}1$[pro-${\alpha}1$(II)] chain (1802 bp) of the skate Raja kenojei, which codes 581 amino acid residues. The partial structure of the pro-${\alpha}1$(II) chain consisted of a part of triple helical region (309 residues) and a C-domain (272 residues). Comparing the chain to other vertebrates showed relatively low homology (about 50%) at the amino acid level. However, eight Cys residues in the C-domain of the skate pro-${\alpha}1$(II) chain were conserved in common with those of other vertebrates. The skate pro-${\alpha}1$ (II) chain mRNA was detected by RT-PCR of various tissues, but was undetected in tissues containing Type II collagen. The low homology and unexpected expression pattern suggest the presence of another mRNA variant of the skate pro-${\alpha}1$(II) chain. The present study is the first report of the primary structure of pro-${\alpha}1$(II) chain in an elasmobranch.

• 한국소프트웨어감정평가학회 논문지
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• 제15권1호
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• pp.115-121
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• 2019

지속적으로 확산되어져 가고 있는 블록체인 시스템과 블록체인 기반의 서비스 시스템의 구조를 분석하였다. 거래 쌍방 간의 신뢰 확보를 위한 제 3 자를 필요로 하지 않는, 분산화된 장부 암호화 시스템 소프트웨어 기술이다. 블록체인은 자료 구조적으로는 링크드 리스트 구조로 되어 있다. 블록체인은 거래 정보를 블록화 하여 다른 블록들과 연결해서 거래 정보를 관리한다. 해시 함수를 사용하여 블록화와 연결을 하게 된다. 결과적으로, 현재의 블록체인 시스템과 블록체인 기반의 서비스 시스템의 구조적 취약성을 발견하였다. 본 논문에서 제시한 블록체인 시스템과 블록체인 기반의 서비스 시스템의 구조적인 문제점 등이 해결되어지게 되면, 다양한 산업적 기여가 예상된다.

• 대한화장품학회지
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• 제22권2호
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• pp.20-40
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• 1996

The oil in water type ME of 4 component system was composed with POE monoalkyl ether and POE sorbitan monoalkyl ester as surfactant, saturated hydrocarbon, side chain structure and aromatic structure as oil, and glycerine as cosurfactant using high pressure homogenizer. The objective of this study was to examine the role of surfactant and oil structure on droplet size and stability. The experimental results showed that the droplet size was smaller with bigger polarity of oil, less hydrocarbon, longer hydrophilic chain of surfactant and higher concentration of glycerine. SQ and LP systems showed very stable but AB and ISB system unstable microemulsion.

• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3711-3718
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• 2012

Here, we report a chain-length dependent morphology and pore structure tailing of mesoporous silica templated from organogels, which is formed by primary alkylamine and ethylene glycol at room temperature. As the chain length of alkylamine changes from 12 to 18, the resulted materials exhibit a morphology change from layers to spheres and platelets, respectively. SEM and TEM observation revealed that these shapes appear to be inherited from their parent organogels. Further pore structure characterization by nitrogen sorption analysis demonstrates that all the resulted silicas exhibit typical IV isotherms indicative of uniform mesopores, and their pore sizes are dependent on the chain length of alkylamine used.

• Bulletin of the Korean Chemical Society
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• 제31권6호
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• pp.1743-1746
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• 2010

• 산업공학
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• 제17권2호
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• pp.169-179
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• 2004

In supply chain management, supplier capacity is very important to meet the customer demand quickly. This paper studies a supplier evaluation structure and then suggests a methodology using fuzzy theory for selecting an effective supplier. Several quantitative and qualitative evaluation factors should be analyzed in the evaluation structure. The qualitative factors includes not only product and service qualities but financial condition. The methodology deals with both the quantitative and qualitative factors together through fuzzy inference. A case study is also presented to show how to choose the best one among potential suppliers.