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유기 발광소자내 dark spot의 마이크로파 근접장 현미경(near-field scanning microwave microscope)을 이용한 연구 (Investigation of dark spots in OLEDs by using a near-field scanning microwave microscope)

  • 윤순일;박미화;유현준;임은주;김주영;이기진
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 디스플레이 광소자분야
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    • pp.147-150
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    • 2003
  • 유기발광소자 안에 존재하는 비발광영역(dark spot)의 전압에 대한 영향을 근접장 마이크로파 현미경(near-field scanning microwave microscope)을 이용하여 관찰하였다. 유기발광소자는 glass/indiumtin oxide(ITO)/Cu-Pc/tris-(8-hydroquinoline)aluminum(Alp3)/aluminum(Al)의 기본구조로 제작하였다. 비발광영역은 ITO 기판을 부분적으로 에칭하여서 형성시켰다. Dark spot에 0~15V 전압을 인가시키면서 인가 전압에 따른 dark spot 구조적 및 전기적 특성을 근접장 마이크로파 현미경 Image의 변화와 반사계수인 $S_11$측정을 통하여 연구하였다.

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무거운 헤일로를 가진 구형 은하의 역학 모형 (DYNAMICAL MODELS OF SPHERICAL GALAXIES WITH MASSIVE HALO)

  • 천문석;고훈성;손영종
    • Journal of Astronomy and Space Sciences
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    • 제20권1호
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    • pp.63-82
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    • 2003
  • Schwarzschild의 선형 계획법을 사용하여 평형상태에서의 구형은하를 기술하는 비 충돌 볼쯔만 방정식의 일반적인 해를 얻었다. 이 계산으로부터 de Vaucouleurs의 광도 법칙을 만족하고 무거운 헤일로를 포함하는 등방성 구형은하의 존재를 확인할 수 있었다. 타원은하에서 속도 분산 곡선이 편평하거나 서서히 증가하는 현상은 암흑물질에 의한 질량대 광도비의 증가로 해석할 수 있다. 이런 경우 암흑물질의 밀도 분포는 core반경이 은하의 유효반경보다 훨씬 작은 값을 갖는다는 사실을 확인할 수 있었다.

Recent progress in dark energy research

  • Park, Chan-Gyung
    • 천문학회보
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    • 제39권1호
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    • pp.32.1-32.1
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    • 2014
  • Astronomical observations strongly suggest that the expansion rate of our universe is currently under acceleration. The nature of the so-called dark energy causing the acceleration is unknown, and it is one of the fundamental mysteries in the present day theoretical cosmology. Here we briefly review the current state of cosmic dark energy research in both theoretical and observational sides. Constraints on dynamical dark energy models (e.g., w-fluid, quintessence, and modified gravity) with recent observational data from type Ia supernovae, cosmic microwave background radiation, and large-scale structures in the universe indicate a preferred direction toward the simplest ${\Lambda}$CDM world model. We also discuss some issues regarding the early dark energy model and the spherical collapse of matter in the presence of dark energy.

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마이크로파 근접장 현미경을 이용한 유기 발광소자내 dark spot 연구 (Investigation of dark spots in organic light emitting diodes by using a near-field scanning microwave microscope)

  • 윤순일;유현준;박미화;김송희;이기진
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.494-497
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    • 2003
  • We report the dark spots in organic light emitting diodes by using a near-field scanning microwave microscope. Devices structure was glass / indium-tin-oxide(ITO) / copper-pthalocyiane(Cu-Pc) / tris-(8-hydroquinoline)aluminum(Alq3) / aluminum(Al). We made artificial dark spots by using a etching technique on a ITO substrate. Near-field scanning microwave microscope images and reflective coefficient of dark spots were measured and compared by the change of various applied voltage changes 0-15V.

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Moment of Inertia of Gas as a Source of Added Gravitational Field in Galaxies

  • Portnov, Yuriy A.
    • Journal of Astronomy and Space Sciences
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    • 제39권2호
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    • pp.59-65
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    • 2022
  • In this paper we propose a new perspective for explaining galaxy rotation curves. We conjecture that there is a gravitational moment of inertia which, together with gravitational mass, contributes to the gravitational potential. We substantiate a formula for the potential created by the moment of inertia. We validate our model by computing orbital rotation velocities for several galaxies and showing that computed rotation velocities correspond to the observed ones. Our proposed approach is capable of accounting for constant gas velocities outside of a galactic disc without relying on the dark matter hypothesis. Furthermore, it addresses several problems faced by the application of the dark matter hypothesis, e.g., the absence of inward collapse of dark matter into a galaxy, the spherical distribution of dark matter around galaxies, and absence of traces of the effect of dark matter in two ultra-diffuse galaxies, NGC 1052-DF2, and NGC 1052-DF4.

Candidates of cold dark matter

  • Choi, Ki-Young
    • 천문학회보
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    • 제44권2호
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    • pp.58.5-58.5
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    • 2019
  • The astrophysical and cosmological observations are consistent with the cold dark matter in the standard cosmology. I review the possible candidates of cold dark matter and their production in the early Universe with their possible detection.

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한복배색에 대한 한미여대생의 선호도 연구 -빨강저고리의 톤변화를 중심으로- (A Study in the Preference of Coloration in Traditional Korean Dress of Korean and American Students - On the Tone Variation of Red Jacket -)

  • 강경자;최수경
    • 한국생활과학회지
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    • 제14권4호
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    • pp.631-643
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    • 2005
  • The purpose of this research is to compare, according to tone variation of a red jacket, the preference of female college students from Korea and the U.S. for coloration in the traditional Korean dress. The results of the research can be summarized as follows: As to a vivid skirt according to tone variation of red jacket, students of both countries showed the different view in the preference for coloration of vivid red skirt and vivid. dark red jacket, and vivid orange skirt and dull red jacket, and vivid yellow skirt and light dull red jacket, and vivid violet skirt and dull red jacket. As to the light skirt according to tone variation of red jacket, student of both countries showed the different view in the preference for coloration of light red skirt and light red jacket, and light orange skirt and light red jacket. As to the dull skirt according to tone variation of red jacket, student of both countries showed the different view in the preference for coloration of dull red skirt and vivid light dull dark red jacket, and dull yellow skirt and light dull red jacket, and dull yellow skirt and light dull red jacket, and dull green skirt and dull red jacket, and dull violet skirt and vivid light dull dark red jacket. As to the dark skirt according to tone variation of red jacket, student of both countries showed the different view in the preference for coloration of dark red skirt and dull dark red jacket, and dark orange skirt and vivid light dull red jacket, and dark yellow skirt and dull red jacket. As to the neutral skirt according to tone variation of red jacket, student of both countries showed the different view in the preference for coloration of white skirt and vivid red jacket, and dark gray skirt and light red jacket.

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Drosophila auraria 의 반문다형현상의 유전학적분석 (Genetic Analysis of the Polymorphism of Color Pattern in Drosophila auraria)

  • 이택준
    • 한국동물학회지
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    • 제7권2호
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    • pp.41-47
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    • 1964
  • D.auraria is a species belonging to the D.melanogaster group, and this species was divided into 3 races(A, B and C race ) by morphoogical difference of the genitals . Korean populations of D.auraria A race are polymorphic with respect to the pigmentation of the abdominal tergites. The female shows two forms of color pattern, dark and light, on the sixth to the ninth tergites, and the male has no distinction shown by the female. Crossing experiments in the laboratory have shown that the difference between these color forms is due to a single pair of allelic genes located on an autosome. In natural populations, the light forms of females are always commoner than the dark one. The number of the light form increases relatively in southern localities and decreases relatively in northern localities. Furthermore, the number of the light form increases relatively in summer and decreases relatively in fall and spring. By genetic analyses of these wild flies, the relation, d/d>d/D>D/D has been disclosed as regards the relative frequencies of the genotypes in natural populations. Three experimental populations have been set up in the laboratory. Homozygous dark forms and homozygous light forms were mixed together and cultured in population cage at the temperature of 25 $^{\circ}C$. Approximately one year later, the frequencies of the light and the dark forms reached an equilibrium , the light one being usually more frequent than the dark one. This indicates that the heterozygous dark form possesses the highest adaptive value, the homozygous light being intermediate and the homozygous dark lowest. In number of adults hached, the homozygous light form was superior to the heterozygous dark form and the homozygous dark form, but the differences are scarcely significant.

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다크 서클(Dark Circles under Eyes)과 담음(痰飮)의 연관성에 관한 연구 (Clinical Study on the Correlation between Retention of Fluid, namely Damum(痰飮) and Dark Circles under Eyes)

  • 조가영;노호식;김수정;김은주;박혜윤;김덕희;김한곤
    • 대한한의진단학회지
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    • 제12권2호
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    • pp.49-60
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    • 2008
  • Objectives: The aim of this study was to investigate correlation of the phlegm-retained fluid, namely Damum(痰飮) and dark circles under eyes. Methods: 2 males and 11 females aged 26-60 years were participated in this study. They were asked the intensity of 29 symptoms related with Damum(痰飮) including dark circle with the questionnaire published by the Journal of the Korea Institute of Oriental Medical Diagnostics. Three skin researchers including OMD graded the dark circles by inspection. We took the pictures around eyes by Facial Stage (Moritex, Japan) and analyzed the skin color by Image-Pro Plus (Media Cybernetics, USA). Results: There was statistically significant correlation between Damum(痰飮) and dark circles measured by self, inspectors and image analysis. Conclusions: In the Oriental Medicine, It is reported that the shadows under eyes are the sign of the retention of fluid, Damum(痰飮). In our study, that shadows, namely dark circles, has correlation with the symptoms of Damum(痰飮). Especially, the correlation between inspected grade and image analysis was very high. According to the above results, it is proved that dark circles under eyes are important diagnostic sign of Damum(痰飮).

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구굴무치과에 속하는 동사리와 얼룩동사리의 Carotenoid 색소성분의 비교 (Comparison of Carotenoid Pigments on Korean Dark Sleeper, Odontobutis platycephala and Dark Sleeper, Odontobutis odontobutis interrupta in the Family Eleotridae)

  • 하봉석;김명선;백승한;김현영;김수영;정계임;권문정
    • 한국식품영양과학회지
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    • 제27권5호
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    • pp.813-820
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    • 1998
  • This study was performed as a part of comparative biochemical studies of carotenoid pigment for the fresh water fish. Carotenoids in integument of Korean dark sleeper, Odontobutis platycephala, and dark sleeper, Odontobutis odontobutis interrupta, which are all the Korean native fresh water fish, were separated by thin layer chromatography, column chromatography and HPLC. The separated carotenoid were then reduced and isomerized by NaBH4 and I2 respectively to investigate UV-Vis spectrophotometeric patterns and chracterized by IR, 1H-NMR and Mass spectrum. The content of total carotenoids in the integument of Korean dark sleeper was 3.01mg% in April, but it was increased to 3.74mg% in September at the near of spawning period. The carotenoid isolated in April consisted of $\beta$-carotene(25.6%), lutein(18.5%) and zeaxanthin(12.0%) as major carotenoids and also contained isocryptoxanthin, diatoxanthin, tunaxanthin, cynthiaxanthin, canthaxanthin and $\alpha$-cryptoxanthin as minor carotenoids. Similarly, in September the carotenoid consisted of $\beta$-carotene(16.5%), zeaxanthin(13.7%) and cynthiaxanthin(13.6%) as major carotenoids and also contained lutein, isocryptoxanthin, tunaxanthin, $\alpha$-cryptoxanthin, diatoxanthin and canthaxanthin as minor carotenoids. At the near of spawning period, the content of cynthiaxanthin and $\alpha$-cryptoxanthin were increased. The content of total carotenoids in the integument of spawning period. T도 carotenoid isolated in April and September consisted of $\beta$-carotene(24.9%, 27.5%), zeaxanthin(14.4%, 20.9%) and lutein(12.6%, 11.4%) as major carotenoids and also contained cynthiaxanthin, tunaxanthin, diatoxanthin, isocryptoxanthin, $\alpha$-cryp-toxanthin and canthaxanthin as minor carotenoids. At the near of spawning period, the content of zeaxanthin was increased, indicating that the carotenoid composition were dependent upon their living conditions and their integument colors. Both Korean dark sleeper and dark sleeper contained high amount of cynthiaxanthin and diatoxanthin which are found as rare carotenoids in the other of fresh water fish. It is interes that they also contained tunaxanthin which is a specific carotenoid in marine fishes.

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