• 천문학회보
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• 제35권1호
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• pp.66.1-66.1
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• 2010

Using two-dimensional numerical hydrodynamic simulations, we investigate the star formation rate (SFR) in turbulent, multiphase, galactic gaseous disks. Our simulation domain is axisymmetric, and local in the radial direction and global in the vertical direction. Our models include galactic rotation, vertical density stratification, self-gravity, radiative heating and cooling, and thermal conduction, but do not include spiral-arm features. Turbulence in our models is driven by momentum feedback from supernova explosion events occurring in localized dense regions formed by thermal and gravitational instabilities. Self-consistent radiative heating, representing enhanced/reduced FUV photons from the star formation, is also taken into account. By controlling three parameters (the gas surface density, the stellar disk density, and the angular rotation rate) that characterize local galactic disks, we explore how the SFR depends on the background environmental state. We also discuss the relation between the SFR and the gas surface density found in our numerical models in comparison with observations.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.3083-3087
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• 2013

Diacetylene lipid monomers possess the capability to self-assemble into vesicles via polymerization under ultraviolet irradiation, resulting in the formation of polydiacetylene (PDA) liposomes. Exposure of the polymerized vesicles to external stimuli is known to induce a unique blue-to-red color transition. The cyclic oligosaccharide ${\alpha}$-cyclodextrin known for its use in many applications, such as drug delivery, purification, and stimulus sensing, is able to form an inclusion complex with poly(ethylene glycol) (PEG) in aqueous solution. In this study, we prepared polymeric liposomes with PEG (PEG-PDA) with the aim of improving the stability of the vesicles and colorimetric response toward ${\alpha}$-cyclodextrin. We demonstrated that PEG-PDA liposome displays unique characteristics compared with native PDA liposome and it also shows apparent chromic properties of the inclusion complex formation with ${\alpha}$-cyclodextrin.

• 한국세라믹학회지
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• 제37권4호
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• pp.332-337
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• 2000

Forming mechanism of fibrous TiC during self-propagating high temperature synthetic reaction was analyzed and suggested. It was revealed that critical temperature for the stable fiber formation was not the melting point of TiC, but the eutectic reaction temperature of TiC and C. Minimum amount of TiC diluent addition required to form fibers was calculated to be 25.6%, which was consistent with the experimental result. Synthesized fibers were found hollow tube-like. The morphology was explained by the diffusion rates of C and Ti in TiC, and by the molar volume chnage of C during the reaction. Expanding shell model was suggested for the hollow fiber formation mechanism.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.123.2-123.2
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• 2011

Self-preservation effect was identified by means of macroscopic dissociation experiments after keeping natural gas hydrate samples at 258 K for 15 days. The hydrate samples were formed using synthetic natural gas hydrate whose compositions are 90% $CH_4$, 7% $C_2H_6$, and 3% $C_3H_8$. In addition, during the formation, heavy hydrocarbons of propane and ethane are found to occupy hydrate cages in a more favorable way than methane so as to change the gas composition after hydrate formation. Experimental results obtained in this study can provide useful information on applications of natural gas hydrate for storing or transporting natural gas in the form of solid hydrate.

• 대한전기학회논문지
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• 제38권10호
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• pp.840-847
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• 1989

It is an important problem that the plasma of high B value is to be confined safely in the research of plasma fusion. So, the Reversed Field Pinch (RFP) plasma has been studied. RFP is stable pinch having self-reversal phenomenon that forms reversed field of itself, but its process of formation is unstable. Therefore, in this paper, we configured the stable RFP by supplying the radio-frequency rotating field just before the RFP is configured by self-reversal phenomenon. Moreover, when conductivity wall is used, toroidal configured by self-reversal phenomenon. Moreover, when conductivity wall is used, toroidal flux is subject to heavy fluctuation in case of high bias field compared with low bias field.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.293-293
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• 2006

Self-assembled nanostructures of block copolymer thin films have gathered significant attention due to their potential applications as templates for nanofabrication. However the lack of a robust strategy to control the structure formation in thin film geometries has been considered a major obstacle for the practical application. In this presentation 'epitaxial self-assembly' will be introduced as a successful strategy to control the self-assembled nanostructure of block copolymer. Chemically patterned surfaces prepared by advanced lithographic techniques successfully registered nanodomains in block copolymer thin film without any single defect over an arbitrarily large area.

• Perspectives in Nursing Science
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• 제12권2호
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• pp.124-127
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• 2015

Purpose: This article discusses nurses' moral dilemma and self-cultivation from the Foucauldian viewpoint. Methods: The philosophical inquiry approach is utilized to analyze the nurses' moral distress. Analyses are based on Foucauldian perspectives. Results: Foucault's codes of conduct comprising the mode of subjection and telos are discussed to explain nurses' moral dilemma. The dual process of caring is also discussed. Conclusion: From dilemmatic experience, nurses practice self-formation or self-cultivation to become more virtuous, well-balanced, or integrated people. Such characteristics form the essence of nursing practice.

• 천문학회보
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• 제46권1호
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• pp.51.1-51.1
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• 2021

Spiral arms greatly affect gas flows and star formation in disk galaxies. We use local 3D simulations of vertically-stratified, self-gravitating, gaseous disks under a stellar spiral potential to study the effects of spiral arms on galactic star formation as well as formation of gaseous spurs/feathers. We adopt the TIGRESS framework to handle radiative heating and cooling, star formation, and ensuing supernova (SN) feedback. We find that more than 90% of star formation takes place inside spiral arms. The global star formation rate (SFR) in models with spiral arms is enhanced by less than a factor of 2 compared to the no-arm counterpart. This supports the picture that spiral arms do not trigger star formation but rather redistribute star-forming regions. Correlated SN feedback produces interarm feathers in both magnetized and unmagnetized models. These feathers live short, have parallel magnetic fields along their length, and are bounded by SN feedback in the lateral direction, in contrast to instability-induced feathers formed in our previous isothermal simulations.

• 한국의류학회지
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• 제25권4호
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• pp.817-827
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• 2001

This study tried to investigate whether characteristics of the perceiver and image of ideal woman made differences in the important factors for the selection clothing and the preference of clothing. A poll of 650 men & women between the ages of 20-39 living in Daegu was taken for this study. Factor analysis, cluster analysis, frequency, ANOVA-test, t-test, and $\chi$$^2$-test were implemented with the SPSS-package. The characteristics of clothing types used in this study included: sexy, masculine, feminine, dramatic, elegant-classic, and casual. The results were as follows. 1. In the situation of first impression formation, the characteristics of the perceiver made differences in the selection of clothing types. Women took self-satisfaction and fashion factors to be more important than men, so did persons in their 20s than 30s. And the unmarried took self-satisfaction factor to be more important than the married. 2. Men and women had different images of the ideal woman. Under special situations of first impression formation, such as, formal blind dates on the condition of marriage and casual blind dates, there were differences in clothing preference.

• 의학교육논단
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• 제23권2호
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• pp.90-103
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• 2021

This study examined the current status of the medical professionalism curriculum in Korea to suggest a plan to move towards the formation of a professional identity. Professionalism education data from 28 Korean medical schools were analyzed, including the number of courses, required or elective status, corresponding credits, major course contents, and teaching and evaluation methods. Considerable variation was found in the number of courses and credits in the professionalism curriculum between medical schools. The course contents were structured to expand learners' experiences, including the essence and knowledge of professionalism, understanding of oneself, social interaction with others, and the role of doctors in society and the healthcare system. The most common teaching methods were lectures and discussions, while reflective writing, coaching, feedback, and role models were used by fewer than 50% of medical schools. Written tests, assignments and reports, discussions, and presentations were frequently used as evaluation methods, but portfolio and self-evaluation rates were relatively low. White coat ceremonies were conducted in 96.2% of medical schools, and 22.2% had no code of conduct. Based on the above results, the author suggests that professional identity formation should be explicitly included in learning outcomes and educational contents, and that professional identity formation courses need to be added to each year of the program. The author also proposes the need to expand teaching methods such as reflective writing, feedback, dilemma discussion, and positive role models, to incorporate various evaluation methods such as portfolios, self-assessment, and moral reasoning, and to strengthen faculty development.