• Title/Summary/Keyword: 자발적 형성

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Polysulfone 제막공정중 Morphology의 형성에 관한 연구

  • 김성철;김제영;백기전;이환광
    • Proceedings of the Membrane Society of Korea Conference
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    • 1997.10a
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    • pp.11-15
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    • 1997
  • Liquid-liquid phase separation에는 nucleation and growth와 spinodal decomposition의 2가지 경로가 있다. 상온에서 고농도의 고분자 용액과 저량의 비용매의 조성의 근처에는 용해도 갭으로 들어가게 되면 비용매에 아주 미량의 고분자가 있는 조성을 갖는 핵이 고분자 용액 내에서 형성되고 이러한 핵은 여러게가 액적의 형태로 주위의 고분자 용액의 gelation에 의해서 성장이 멈출 때까지 커지게 된다. 여기서 어떤 고분자 상이 nucleation되는지가 매우 중요하게 된다. 실제 우리가 상전이 막을 제조할 경우는 대부분 10wt% 이상의 고분자 농도이므로 polymer-poor상이 nucleation이 된다. Spinodal decomposition의 경우는 용해도 갭을 빠르게 통과해서 nucleation이 일어나지 않고 spinodal line을 지나는 경우이다. 이러한 경우의 용액은 매우 불안정해서 약간의 농도 변화에도 자발적인 상분리가 일어나서 polymer-poor상과 polymer-rich상이 서로 얽혀져 있는 network구조를 형성하게 된다.

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The Utilization of Oleogels for Cosmetics (화장품에서의 올레오겔 이용)

  • Cho, Wan-Goo
    • Journal of the Korean Applied Science and Technology
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    • v.30 no.1
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    • pp.16-34
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    • 2013
  • Oleogels may be defined as lipophilic liquid and solid mixtures. The solid lipid materials (oleogelators) with less than 10 wt.% can entrap bulk liquid oil by ways of the formation of network of oleogelators in the bulk oil. The oelogelators can be grouped into two: self-assembly system and crystal particles system. This article reviewed recent work on the formation of oleogels using various types of oleogelators. The fundamental aspects of the formation of lipid network are discussed with a special emphasis on crystal particle based oleogels. The potential applications of oleogels for cosmetics are also described.

지식경영 추진 과정과 성과: 삼성그룹 계열사에 대한 비교 사례연구

  • Im, Ung-Bin;Jo, Nam-Jae
    • 한국디지털정책학회:학술대회논문집
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    • 2007.06a
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    • pp.215-221
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    • 2007
  • 본 연구는 지식경영 시스템을 구축한 삼성그룹 중 5개사 사례분석을 통해 공통점과 차이점을 분석하고 일반화된 지식경영 추진방안 시사점을 도출하여 지식경영 도입을 검토하고 있는 기업에게 지식경영 구축의 방향을 설정하는데 도움을 주고자 한다. 분석결과 최고 경영층 지원을 비롯한 지식경영 공감대 형성이 기초가 되어 자발적인 임직원 참여가 중요한 요소로 대두되었다.

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DELAYED TOOTH ERUPTION GUIDED BY SPONTANEOUS TOOTH ERUPTION: CASE REPORT (맹출 지연 영구치의 자발적 맹출 유도 : 증례보고)

  • Kwon, Ji-Hoon;Park, Ho-Won;Lee, Ju-Hyun;Seo, Hyun-Woo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.34 no.4
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    • pp.694-699
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    • 2007
  • Delayed tooth eruption is the most commonly encountered deviation from normal eruption time. Racial, ethnic, sexual, and individual factors can influence eruption and are usually considered in determining the standards of normal eruption. Delayed tooth eruption was affect to the dentition and facial growth, so that when it occurred careful evaluation should be performed to establish the cause and the treatment plan accordingly. Present 3 cases of delayed tooth eruption by periapical lesion, underdevelopment of incisior and compound odontoma were successfully treated. In these cases, we could observe spontaneous eruption of the delayed erupting tooth after removal of interrupting factor and space regaining with maintaining.

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PHYSIOLOGIC ERUPTION INDUCTION OF TRANSPOSED IMPACTED UPPER INCISORS THROUGH AUTOTRANSPLANTATION (변위매복된 상악전치의 자가이식을 통한 자발적 맹출 유도)

  • Kim, Jae-Gon;Lee, Doo-Cheol;Oh, Kyong-Seon;Baik, Byeong-Ju
    • Journal of the korean academy of Pediatric Dentistry
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    • v.28 no.2
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    • pp.281-286
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    • 2001
  • The treatment method of impacted tooth is various from simple observation to surgical exposure and orthodontic methods, autotransplantation is concerned to severe malposed impacted tooth. Autotransplantation is the transplantation of embedded, impacted, of unerupted tooth, into extraction socket of surgically prepared in the same individual. Autotransplantation of tooth with $\frac{1}{2}{\sim}\frac{3}{4}$ root development provides a good chance of easily extracted, a little complication, pulp survival, and complete root formation. Transplantation of uncompleted root apex tooth is aim to pulpal healing, not endodontic treatment. The case which were treated with autotransplantation is reported, and induced normal physiologic eruption and good dental alignment.

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ERUPTION GUIDANCE OF IMPACTED MANDIBULAR FIRST MOLAR BY SURGICAL EXPOSURE (외과적 노출술을 이용한 매복된 하악 제1 대구치의 자발적 맹출유도)

  • Kim, Eun-Jung;Kim, Nan-Jin;Jo, Ho-Jin;Kim, Hyun-Jung;Kim, Young-Jin;Nam, Soon-Hyeun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.4
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    • pp.598-604
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    • 2004
  • Impaction of mandibular first molar is relatively rare and its overall frequency has been reported to be 0.01%. The etiology of impaction are lack of eruption space, physical obstacles such as supernumerary teeth, odontomas or odontogenic tumors, hereditary factors, functional disturbances of endocrine glands and traumas. Impaction of mandibular first molar can result in a short lower facial height, formation of a follicular cyst, pericoronal inflammation, resorption of the roots of neighboring teeth and malocclusion. The treatment options available for impacted teeth include surgical exposure, orthodontic forced eruption, surgical repositioning and surgical removal of unerupted molar. This report presents two cases of distally tilted and impacted mandibular first molars which were treated by surgical exposure. In these cases, we could observe spontaneous eruption of the impacted mandibular first molars after surgical exposure.

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A Theoretical Model of Executive Voluntary Turnover (기업내 임원의 자발적 이직에 관한 이론적 모형)

  • Choi, Dongwon
    • Journal of Digital Convergence
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    • v.19 no.8
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    • pp.173-184
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    • 2021
  • For the current organizations, retaining executive members is one of the most important functions of human resource management. Given that importance, although executives' mobility becomes prevalent, most prior studies tended to focus on involuntary turnover of executive members. To fill this gap, the current theoretical paper suggests a model of executive voluntary turnover, drawing on the lierature of employee mobility and entrepreneurship. First, running a new business as a CEO negatively affects prior-firm performance, but collaboration between two firms mitigate the negative association. Second, spin-off positively affects prior-firm performance, but this is weakened as spin-off firm performance decreases. Finally, moving to a competitor negatively, while moving to a collaborator positively affects prior-firm performance.

Analyses of Brand Community Characteristics, Members' Behavioral Patterns & Participation Experiences, and Quality of Relationship according to Community Formation Orientation: Comparisons between Maker Oriented Community and Customer Oriented Community (브랜드 커뮤니티 형성과정에 따른 커뮤니티의 특징, 구성원의 행태와 참여경험 및 관계의 질에 대한 분석)

  • Yoo, Chang-Jo;Jung, Hye-Eun
    • Proceedings of the Korean Association for Survey Research Conference
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    • 2005.12a
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    • pp.187-220
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    • 2005
  • The purpose of this study is to analyze supporters' community formation motives/ Process/consumption experiences and community characteristics. For this purpose, this study collected the data using ethnographic interview. participant observation, documents and media reports. The results of this study show that supporters communities' formation and diffusion process were influenced by individual characteristics(e.g., personality, hobby and etc.), community characteristics(e.g.,team performance, star player, facilities and etc.) and external factors(ex: media movement etc.) and supporters have experienced various emotions such as intimacy. cohesion, pride and so on through various activities at on-line and off-line site. Community characteristics were classified into we-ness, rituals/traditions, moral responsibility. We found that we-ness influenced emotional dimensions such as joy, pleasure, fun and excitement. rituals and traditions made members feel passion. hope. love and vitality. and moral responsibility provided satisfaction. enthusiasm anxiety. regret and so on. Also, emotional attachment and brand loyalty were increased by these experiential aspects of community consumption.

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Growth characterization of ZnO nanowires grown on thermally annealed silver thin film as a masking layer by hydrothermal method

  • Kim, Jong-Hyeon;Kim, Seong-Hyeon;No, Im-Jun;Jeong, Dae-Yong;Jo, Jin-U
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.475-475
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    • 2011
  • 현재 수열합성법으로 이용하여 1차원으로 수직 성장한 ZnO 나노와이어는 밴드 갭이 3.37ev로 큰 밴드 갭을 갖는 물질이며 밀도 조절이 매우 어려운 것으로 알려져 있다. ZnO 나노와이어는 기존의 리소그래피 기반을 둔 Top-Down 방식과 달리 자발적인 형성과정으로 높은 결정성을 가지게 되는데, 이는 ZnO 나노와이어가 큰 종횡비 와 전자친화도를 가지고 있어 높은 전계방출 효과를 기대하게 되는 부분이다. 본 연구에서는 실버를 열처리하여 형성된 실버 나노파티클을 마스킹층으로 사용하여 ZnO 나노와어의 밀도 조절을 하고자 하였다. 실버막을 AZO seed layer 기판 위에 증착한뒤 $200{\sim}600^{\circ}C$ 까지 열처리 후 수열합성법을 이용하여 ZnO nanowire를 성장하였다. 또한 전구체인 ZN(NO3)2${\cdot}$6H2O 와 HMT 에 각각 Ammonium chloride와 PEI를 첨가하였고, PEI 의 몰농도를 변화하여 성장된 ZnO 나노와이어의 구조적, 광학적 특성을 평가함으로서 전자소자 적용 가능성을 확인하였다.

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Two-dimensional Assembly of Organically Functionalized Ag Nanoparticles at Air-water Interface (공기와 물이 형성하는 계면에서 발생하는 유기적으로 기능화된 은 나노 입자들의 2차원 조립)

  • Chung, Sungwook
    • Applied Chemistry for Engineering
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    • v.28 no.1
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    • pp.125-131
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    • 2017
  • We report organically functionalized Ag nanoparticles spontaneously form two-dimensional (2D) novel superstructures at the air-water interface. Analysis of the superstructures suggests that the 2D assembly of Ag nanoparticles originates from a subtle interplay between characteristic inter-particle interactions that can be readily controlled by changing the sizes of nanoparticle metal core and surfactants. Such structures have potential uses in nanostructured functional materials, catalysis, and device applications.