• Title/Summary/Keyword: chain orientation

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Diffusion Behavior of n-Alkanes by Molecular Dynamics Simulations

  • Goo, Geun-Hoi;Sung, Gi-Hong;Lee, Song-Hi;Chang, Tai-Hyun
    • Bulletin of the Korean Chemical Society
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    • v.23 no.11
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    • pp.1595-1603
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    • 2002
  • In this paper we have presented the results of diffusion behavior of model systems for eight liquid n-alkanes ($C_{12}$-$C_{44}$) in a canonical (NVT) ensemble at several temperatures using molecular dynamics simulations. For these n-alkanes of small chain length n, the chains are clearly <$R_{ee}^2$>/6<$R_g^2$>>1 and non-Gaussian. This result implies that the liquid n-alkanes over the whole temperatures considered are far away from the Rouse regime, though the ratio becomes close to the unity as n increases. Calculated self-diffusion constants $D_{self}$ are comparable with experimental results and the Arrhenius plot of self-diffusion constants versus inverse temperature shows a different temperature dependence of diffusion on the chain length. The global rotational motion of n-alkanes is examined by characterizing the orientation relaxation of the end-to-end vector and it is found that the ratio ${\tau}1/{\tau}2$ is less than 3, the value expected for a isotropically diffusive rotational process. The friction constants ${\xi}$of the whole molecules of n-alkanes are calculated directly from the force auto-correlation (FAC) functions and compared with the monomeric friction constants ${\xi}_D$ extracted from $D_{self}$. Both the friction constants give a correct qualitative trends: decrease with increasing temperature and increase with increasing chain length. The friction constant calculated from the FAC's decreases very slowly with increasing temperature, while the monomeric friction constant varies rapidly with temperature. By considering the orientation relaxation of local vectors and diffusion of each site, it is found that rotational and translational diffusions of the ends are faster than those of the center.

Analysis of Research Trends in the Field of Blockchain-based Supply Chain Traceability (블록체인 기반 공급망 추적성 분야 연구 동향 분석)

  • Lee, Jong-Ok;Kwon, Oh-Hun
    • Informatization Policy
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    • v.28 no.2
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    • pp.3-33
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    • 2021
  • The purpose of this study is to analyze the research trends in the field of Blockchain that is one of the core technologies of the 4th Industry, and present future research orientation. In this study, (1) Blockchain technologies in business perspective are summarized; (2) analysis criteria of Blockchain fields are established; and (3) results of analysis are presented and future research orientation is proposed. Major findings are as follows: (1) related research is being activate with the advent of the 3rd generation blockchain which aims for distributed applications. (2) major concerns of the technology (engineering) field is blockchain scalability and of the business (application) field is blockchain-based supply chain traceability. (3) Compared to overseas, domestic research results are very poor. (4) to catchup the gap, the spreading of awareness that blockchain is not a technology but a business means is required.

Antecedents and Consequences of Cooperation in Retail Voluntary Chain (소매점 볼런터리 체인 활성화의 선행요인과 결과)

  • Yi, Ho-Taek
    • Journal of Distribution Science
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    • v.14 no.6
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    • pp.65-73
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    • 2016
  • Purpose - Recently, the management conditions of small independent retailers are getting worse everyday as large-scale marts and franchised convenience stores are increasing. The objective of this research is to find out the antecedents and consequences of cooperation in voluntary chain in order to enhance small independent retailer's competitiveness. Voluntary chains, also called affiliation or symbol groups, or allied group represent a high market shared in some European countries like Italy, France, and Germany. Nevertheless, there are still limitations in this research from academic fields. Drawing from network theory, the author investigates the relationship between antecedent factors in voluntary chain cooperation, such as participation benefits, justice of compensation, and autonomy in voluntary chain, and relationship specific asset. The author also attempts to examine the relationship between the relationship specific asset and cooperation of voluntary chain member shop and cooperation and consequence factors of voluntary chain cooperation, such as efficiency, group cohesiveness, and long-term relationship. Research design, data, and methodology - The author presented conceptual framework integrating the major antecedents and consequences of voluntary chain cooperation. The data were collected from 174 independent small retailers who joined K-voluntary chain. K-voluntary chain consists of small independent retailers. In accordance with their status, each entrepreneur associated with the voluntary group can own one or more outlets and can be a part of the life and the decision-making process of the group. This participation is not based on company turnover or on the number of outlets, but based on a one member, one vote system. To verify the research model and test hypotheses, the author carefully investigated the reliability, content validity, convergent validity, and discriminant validity of the proposed model. The data were analyzed by using SPSS 18.0 and AMOS structural equation modeling program. Results - The results of this study are as follows. First, as antecedent variables, participation benefits and justice of compensation have positive effect on the relationship specific assets of voluntary chain members. Second, voluntary chain members' relationship specific asset also directly related to the level of its cooperation to chain headquarter. Third, cooperation of voluntary chain member shop facilitates efficiency, group cohesiveness, and long-term relationship. Unexpectedly, there are no effect autonomy in voluntary chain to relationship specific asset. Conclusions - This research shows several theoretical and practical implications to both marketing scholars and marketers. In terms of theoretical implications, this study applies to network theory and network theory variables to explain the antecedent and consequence factors of cooperation in voluntary chain. From the point of view from business management, most of all, this study shows the way how to reinforce competitiveness of voluntary chain. Specifically, it is necessary for voluntary chain headquarter to give higher level of participation benefit and justice of compensation to its members. Second, the results also indicate what the consequence factors of cooperation in voluntary chain. In other words, to increase the level of marketing efficiency, group cohesiveness, long-term orientation in retail voluntary chain, and chain headquarter need to facilitate participants' cooperation.

Development of Supply Chain Management Education Programs for the Construction Industry (건설산업에서의 Supply Chain Management 교육 프로그램 개발 방안 연구)

  • Lee, Tai Sik;Park, Eun Soo;Lee, Dong Wook
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.31 no.2D
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    • pp.275-284
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    • 2011
  • In the process of supply chain management (SCM), the supply chain outside of the production line contributes up to 60~70% of value added. Faced with ever increasing competition, companies are exercising the efforts for cost reduction and process improvement. At the center of the efforts is the reengineering of supply chain for the improvement of customer orientation and customer satisfaction. In spite of the need, the contractual hierarchy with subcontractors stands in the implementation of SCM in the construction industry. Although the construction industry has its own unique characteristics, The process of SCM can be adopted into the industry for improving the effectiveness of the business process. This study presents the methods that can foster SCM professionals through the development of SCM professional education contents, and suggests the activations for applying construction SCM.

Chain orientation and Degradation Behavior of Poly[(R)-3-hydroxybutyrate] Lamellar Crystals

  • Lee, Won Gi;Jo, Nam Ju;Ha, Chang Sik
    • Bulletin of the Korean Chemical Society
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    • v.22 no.8
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    • pp.872-876
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    • 2001
  • Topological changes caused by the alkaline and enzymatic attacks of solution-grown, chain-folded lamellar crystals (SGCs) of poly[(R)-3-hydroxybutyrate] P(3HB) have been studied in order to investigate the chain-folding structure in P(3HB) crystal regions. NaOH and an extracellular PHB depolymerase purified from Alcaligenes faecalis T1 were used for alkaline and enzymatic hydrolysis, respectively. The measurements were performed on crystals attached to a substrate which is inactive to degradation mediums. Both alkaline and enzymatic attacks lead to a breakup of the lamellar crystals along the crystallographic b-axis during initial erosion. Since hydrolysis preferentially occurs in amorphous regions, this morphological result reflects relatively loosely packed chains in core parts of lamellar crystals. Additionally, it was supported by the ridge formation along the b-axis in the lamellar crystals after thermal treatment at a low temperature because of the thermally sensitive nature of the loosely packed chains in lamellar crystals. However, the alkaline hydrolysis accompanied the chain erosions or scissions in quasi-regular folded lamellar surfaces due to smaller size of alkaline ions in comparison to the enzyme, resulting in the decrease of molecular weight.

Design of a Knowledge Oriented Global Supply Chain Management Model and Analysis of Its Effectiveness (지식지향 글로벌 공급사슬관리 모형의 설계와 효과분석)

  • Lee, Sang Yoon;Lee, Ju Hyun;Kim, Young Ki
    • Journal of Korea Port Economic Association
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    • v.29 no.4
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    • pp.201-222
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    • 2013
  • The purpose of the present study is to analyze how and to what degree multinational companies organize and operate their supply chains in accordance with the strategic resource of knowledge in their multinational management, and what kind of influence knowledge oriented global supply chain management has on the management performance of multinational corporations. For this purpose, the current research proposed a measurement model to provide specific shape to the concept of knowledge oriented global supply chain management by adopting the knowledge creation process proposed by Nonaka (1994), and conducted an empirical analysis of what kind of impact the knowledge management system and the knowledge creation process of companies have on the performance of their global supply chain management. The result of the empirical analysis of 113 multinational companies verified the validity and reliability of the measurement model proposed in this study. In addition, the comparative study of the sampled companies by grouping them according to the level of knowledge orientation in global supply chain management indicated that the enterprises that effectively manage the knowledge created within the global supply chain presented overall superiority on the performance of global supply chain management.

Position and Orientation Recognition for Adjusting Electronic Tuners (전자 튜너 조정을 위한 위치와 방향 인식)

  • Yang, Jae-Ho;Kong, Young-June;Lee, Moon-Kyu
    • Journal of the Korean Society for Precision Engineering
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    • v.16 no.2 s.95
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    • pp.39-49
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    • 1999
  • This paper describes the development of a vision-aided position and orientation recognition system for automatically adjusting electronic tuners which control the waveform by rotating variable resisters. The position and orientation recognition system estimates the center and the angle of the tuner grooves so that the main controller may correct the difference from the ideal position and thereby manipulate the variable resisters automatically. In this paper a robust algorithm is suggested which estimates the center and the angle of the tuner grooves fast and precisly from the source image with lighting variance and video noise. In the algorithm morphological filtering, 8-chain coding, and invariant moments are sequentially used to figure out image segments concerned. The performance of the proposed system was evaluated using a set of real specimens. The results indicate the system works well enough to be used practically in real manufacturing lines. If the system adopts a high speed frame grabber which enables real time image processing, it can also be applied to positioning of robot manipulators as well as automated PCB adjusters.

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Orientation of Poly(styrene-b-methylmethacrylate) thin films deposited on Self-Assembled Monolayers of phenylsilanes

  • Kim, Rae-Hyun;Bulliard, Xavier;Char, Kook-Heon
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.311-311
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    • 2006
  • The morphology of Poly(styrene-b-methylmethacrylate) (P(S-b-MMA)) block copolymer thin films deposited on silicon wafers was controlled by treating the substrates with Self-Assembled Monolayers (SAM) of phenylsilanes with different alkyl chain lengths. It was found that the treatment with SAM strongly modified the substrates properties, especillay the surface energy, as compared with bare silicon oxide. By futher adjusting the molecular weight of P(S-b-MMA), a variety of morphologies could be generated, including a perpendicular orientation of lamellea of PS and PMMA, which is required for industrial applications.

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Molecular orientation and electrical properties of TCNQ ultrathin organic films (TCNQ 유기초박막의 분자 배향 및 전기적 특성)

  • 이용수;신동명;김태완;강도열
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1997.11a
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    • pp.5-8
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    • 1997
  • A study on the electrical conduction characteristics of the ultrathin organic films is one of the important factors for the development of molecular electronic devices. The Langmuir- Blodgett(LB) technique has recently been attracted interest as a method of the deposition ultrathin films. We hate fabricated N-docosyl N\`-methyl viologen-diTCNQ(DMVT) anion radical LB film and investigated the molecular orientation and electrical conduction characteristics. We have measured infrared transmission-reflection spectra. The alkyl chain is found to he well-ordered with the tilt angle of 13$^{\circ}$ with respect to the substrate surface normal and the TCNQ plane is tilted at 76$^{\circ}$ the surface normal. In ESR spectrum, we confirmed that a half-amplitude linewidth is clearly dependent on the incident angle, which indicates conducting species change. The in-plane conductivity of 31 lagers is approximately 1.33$\times$10$^{-6}$ S/cm. The ohmic behaviour was observed below 0.6 V, when current-voltage(I-V) characteristics was measured verically.

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The Effect of Factors Influencing RFID Adoption and Performance and the Moderating Effect of Environment Uncertainty within Supply Chain (공급사슬망 내부에서 RFID 채택과 성과에 영향을 주는 요인과 환경 불확실성의 조절효과에 대한 연구)

  • Kim, Sang-Hyun;Song, Young-Mi
    • Journal of Korea Society of Industrial Information Systems
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    • v.16 no.3
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    • pp.101-119
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    • 2011
  • A empirical study investigating firms' attitudes and behaviors regarding of RFID technology within supply chain is very limited. Thus, this study examines the determinants influencing firms' adoption and performance of RFID within the supply chain. Particularly, this study focus on the impacts of the companies' relationship characteristics, including strategic fit, interdependence, compatibility, and long-term orientation affection RFID adoption and performance within the supply chain. Furthermore, the study includes environment uncertainty as a moderating effect between relationship characteristics and RFID adoption. The proposed research model was tested using structural equation modeling from 227 employees. Results of this study support the proposed hypotheses. The implication of this study suggest a new theoretical framework explaining RFID adoption and performance with the supply chain.