• 제목/요약/키워드: light curves

검색결과 444건 처리시간 0.026초

공초점 원리와 광섬유 광원 변조를 이용한 무한보정 현미경 자동초점 (Autofocus of Infinity-Corrected Optical Microscopes by Confocal Principle and Fiber Source Modulation Technique)

  • 박정재;김승우;이호재
    • 한국광학회지
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    • 제15권6호
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    • pp.583-590
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    • 2004
  • 비전을 이용한 광학식 검사공정이나 그 밖의 광학 현미경을 이용한 측정에 있어서 초점조절은 곧바로 측정 정밀도에 영향을 주는 중요한 요소이다. 본 논문에서는 핀홀 대신 광섬유를 사용하는 공초점 현미경 구조와 하나의 광섬유가 광원과 검출기의 역할을 동시에 수행하는 상반구성(reciprocal scheme)을 적용함으로써 간결하게 시스템을 구성하면서 광축 정렬을 용이하게 하였으며, 압전소자(PZT)를 이용한 광섬유 광원의 광축 방향 변조를 통해 방향 정보가 실린 초점오차 신호를 획득함으로써 빠른 초점조절을 구현하였다. 대물렌즈 변조방식과 달리 광원 변조방식은 현미경 시스템에 미치는 물리적 영향을 줄일 수 있으며, 기존의 장치에 탑재가 비교적 용이하다는 장점을 갖는다. 본 논문에서는 변조 진폭과 시편의 반사도 및 기울기 변화에 따른 초점오차 신호의 변화를 측정하였으며, 거울 시편에 대한 초점조절을 통해 본 시스템의 성능을 평가해 보았다. 또한 종방향 특성곡선의 반치폭 비교실험을 통해 광원 변조는 광축 방향 분해능에 영향을 주지 않음을 확인하였다.

오존 감수성 및 저항성 고추 품종의 생리생태 변화 (The Ecophysiological Changes of Capsicum annuum on Ozone-Sensitive and Resistant Varieties Exposed to Short-Term Ozone Stress)

  • 윤성철
    • 한국환경농학회지
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    • 제23권3호
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    • pp.128-132
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    • 2004
  • 공시된 세 품종의 고추에 대한 단기간의 오존 처리로 잎에서 나타나는 전형적인 증상은 갈색의 괴사 반응이었으며, 괴사가 심했던 오존 감수성인 다보탑과 같은 농도에서 괴사가 전혀 없었던 부촌 품종을 오존 저항성 품종으로 판단되었다. 고추의 두 품종에서 오존 처리에 의해 광합성 및 기공 전도도 등의 생리생태적 저해가 뚜렷이 나타났다. 그러나 잎에서 가시피해의 정도와 생리생태적 저해 정도와의 상호 연관성으로 고추에서의 오존 저항성 기작을 설명하고자 하였으나 생리생태적 반응으로 잎에서 발생하는 오존 저항성의 기작을 설명할 수 없었다. 다만, 고추에서 오존 처리에 의한 광합성 감소는 뚜렷한 기공전도도 감소와 명반응에서 광합성 기구들의 손상에 기인한다고 여겨진다. 그러나, 암반응에서 생화학적 반응을 설명할 수 있는 A-Ci curve 상에서는 오존 처리에 따른 효과를 찾을 수 없었다.

A SEARCH FOR AGN INTRA-DAY VARIABILITY WITH KVN

  • LEE, TAESEOK;TRIPPE, SASCHA;OH, JUNGHWAN;BYUN, DO-YOUNG;SOHN, BONG-WON;LEE, SANG-SUNG
    • 천문학회지
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    • 제48권5호
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    • pp.313-323
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    • 2015
  • Active galactic nuclei (AGN) are known for irregular variability on all time scales, down to intra-day variability with relative variations of a few percent within minutes to hours. On such short timescales, unexplored territory, such as the possible existence of a shortest characteristic time scale of activity and the shape of the high frequency end of AGN power spectra, still exists. We present the results of AGN single-dish fast photometry performed with the Korean VLBI Network (KVN). Observations were done in a “anti-correlated” mode using two antennas, with always at least one antenna pointing at the target. This results in an effective time resolution of less than three minutes. We used all four KVN frequencies, 22, 43, 86, and 129 GHz, in order to trace spectral variability, if any. We were able to derive high-quality light curves for 3C 111, 3C 454.3, and BL Lacertae at 22 and 43 GHz, and for 3C 279 at 86 GHz, between May 2012 and April 2013. We performed a detailed statistical analysis in order to assess the levels of variability and the corresponding upper limits. We found upper limits on flux variability ranging from ~1.6% to ~7.6%. The upper limits on the derived brightness temperatures exceed the inverse Compton limit by three to six orders of magnitude. From our results, plus comparison with data obtained by the University of Michigan Radio Astronomy Observatory, we conclude that we have not detected source-intrinsic variability which would have to occur at sub-per cent levels.

Physical Properties of Transiting Planetary System TrES-3

  • Lee, Jae-Woo;Youn, Jae-Hyuck;Kim, Seung-Lee;Lee, Chung-Uk;Koo, Jae-Rim;Park, Byeong-Gon
    • 천문학회보
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    • 제35권2호
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    • pp.65.2-65.2
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    • 2010
  • We present four new transits of the planetary system TrES-3 observed between 2009 May and 2010 June. Among those, the third transit by itself indicates possible evidence for brightness disturbance, which could originate from a starspot or an overlapping double transit. A total of 107 transit times, including our measurements, were used to determine the improved ephemeris with a transit epoch of $2454185.910950\pm0.000073$ HJED (Heliocentric Julian Ephemeris Date) and an orbital period of $1.30618698\pm0.00000016$ d. We analyzed the transit light curves using the JKTEBOP code and adopting the quadratic limb-darkening law. In order to derive the physical properties of the TrES-3 system, the transit parameters are combined with the empirical relations from eclipsing binary stars and stellar evolutionary models, respectively. The stellar mass and radius obtained from a calibration using $T_{eff}$, log $\rho$ and [Fe/H] are in good agreement with those from the isochrone analysis within the uncertainties. We found that the exoplanet TrES-3b has a mass of $1.93\pm0.07\;M_{Jup}$, a radius of $1.30\pm0.04\;R_{Jup}$, a surface gravity of $28.2\pm1.1\;m\;s^{-1}$, a density of $0.82\pm0.06\;\rho_{Jup}$, and an equilibrium temperature of $1641\pm23K$.

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미이스 반 데르 로에 주택과 르 꼬르뷔제 주택의 비교 연구 (A Comparative Study of the Houses of Mies van der Rohe and Le Corbusier)

  • 김용립
    • 한국실내디자인학회논문집
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    • 제13권5호
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    • pp.21-31
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    • 2004
  • There are probably no architects of the 20th Century who had more influence on modern architecture than Mies van der Rohe and Le Corbusier. Although the two architects share one thing in common, namely, both are master of modernism, each has developed unique architecture of his own. The objective of this study is to investigate the characteristics of their works through a comparison analysis of the Ideas, design principles and architectural language reflected in the works, focusing on the houses. this study will also aim to provide a foundation for a new design that harmonizes the design principles and architectural language of the two. Through the study the following common points and differences were found between the houses of the two. A) Common points: Both architects avoided ornamentation In houses while placing weight on the functions of houses and they tried to plan rational floor plans by separating the wall from the structure. B) Differences: \circled1 The houses of Mies express the structure in a straight forward manner, while those of Corbusier are formative houses focusing more on shapes. \circled2 The shapes of the houses of Mies are limited to basic shapes, quadrangle while those of Corbusier employ various geometric curves. \circled3 Using steel and glass, the houses of Mies are light and transparent. On the contrary, using concrete, the houses of Corbusier are somewhat bulky with Three-dimensional changes. \circled4 The houses of Mies show the value of moderation based upon the classical principles of design, while the houses of Corbusier show the value of moderation based upon geometry. \circled5 The houses of Mies feature horizontal intoners with flexibility. However, Corbusier's houses have vertical interiors with some changes in the cross sections. \circled6 In terms of material, the interiors of Mies' houses employ materials with various tones and textures, while interiors of Corbusier's houses are painted in simple white. Summing up these characteristics, it could be said that the houses of Mies have logical and rational beauty, whereas the houses of Corbusier have more emotional beauty.

오페라 무대의상의 현대적 재해석 - 로코코시대의 장식요소를 중심으로 - (Modernistic reinterpretation of stage costumes in the opera - Focusing on the decorative elements of the Rococo mode -)

  • 김해연;박선경;이은정
    • 복식문화연구
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    • 제25권4호
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    • pp.458-475
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    • 2017
  • Opera is the most comprehensive musical art. In recent years, contemporary opera worlds has seen a variety of attempts to reinterpret operas of the past in a modern light. This has resulted in a dramatic change in the production of musical style and stage art. The purpose of the study was to modernize and streamline opera costumes by extending the scope of existing stage costume design, through the reinterpretation and application of the decorative elements in the Middle Age of Rococo, such as ruffles, frills, shirring, embroidery, buttons, etc., in such a way as to effectively communicate the moods of an opera to a modern audience. The costumes of the Rococo period were reinterpreted in a modern way, with the following results. First, in this work, the male main character was played by a bass to express the image of an older, lazy, rich man. A key element in modernizing the stage costume was selection of the costume color in such a way as to visually represent the voice tones sung by the major characters in the opera. Second, the maid hat and aprons were decorated with frills by applying the curves of Rocaille decoration from the Rococo period symbolize the role of the maids. This represented the distinction between occupation according to class and status at that time, while also expressing the ideals of modern feminine beauty. This makes for more comfortably-worn costumes, and is economical for production expenses. In the future, the stage costume design for classical opera will need to be revised consideration of a modern viewpoint.

PPV를 이용한 유기 박막 EL 소자의 전기-광학적특성 (Electro-optical properties of organic thin film EL device using PPV)

  • 김민수;박이순;박세광
    • 센서학회지
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    • 제7권2호
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    • pp.97-102
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    • 1998
  • PPV(poly(p-phenylenevinylene))를 발광체로 이용한 유기 박막 EL 소자를 다양한 구조와 조건으로 제작하였으며, 그 전기-광학적 특성을 평가하였다. 제작된 EL 소자는 단층구조(ITO(indium tin oxide)PPV/Mg), 이층구조 (ITO/PVK(poly(N-vinylcarbazole))/PPV)Mg와 ITO/PPV/Polymer matrix+PBD/Mg) 그리고 삼층구조 (ITO/PVK/PPV/PS(polystyrene)+PBD(butyl-2-(4-biphenyl)-5-(4-tert-butylphenyl-1,3,4-oxadiazole))/Mg)를 가지며, 그들의 전기광학적 특성을 상호 비교하였다. 이층구조(ITO/PPV)Polymer matrix+PBD/Mg)에서는 PMMA (poly(methyl methacrylate)), PC(polycarbonate) PS 와 MCH(side chain liquid crystalline homopolymer)를 고분자 메트릭스로 사용하였으며, 특히, PS 고분자 메트 릭스를 전자수송층으로 사용하는 경우에 전자수송제인 PBD의 농도에 따른 발광휘도 특성을 구하였다. 제작된 소자의 인가전압에 따른 전류, 휘도특성을 분석한 결과 터널링효과를 나타내었고 안정된 발광특성을 가진다는 것을 알 수 있었다.

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The Role of Magnetic Topology in the Heating of Active Region Coronal Loops

  • Lee, Jin-Yi;Barnes, Graham;Leka, K.D.;Reeves, Katharine K.;Korreck, K.E.;Golub, L.;Deluca, E.E.
    • 천문학회보
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    • 제36권2호
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    • pp.86.2-86.2
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    • 2011
  • We investigate the evolution of coronal loop emission in the context of the coronal magnetic field topology. New modeling techniques allow us to investigate the magnetic field structure and energy release in active regions (ARs). Using these models and high-resolution multi-wavelength coronal observations from the Transition Region and Coronal Explorer and the X-ray Telescope on Hinode, we are able to establish a relationship between the light curves of coronal loops and their associated magnetic topologies for NOAA AR 10963. We examine loops that show both transient and steady emission, and we find that loops that show many transient brightenings are located in domains associated with a high number of separators. This topology provides an environment for continual impulsive heating events through magnetic reconnection at the separators. A loop with relatively constant X-ray and EUV emission, on the other hand, is located in domains that are not associated with separators. This result implies that larger-scale magnetic field reconnections are not involved in heating plasma in these regions, and the heating in these loops must come from another mechanism, such as smallscale reconnections (i.e., nanoflares) or wave heating. Additionally, we find that loops that undergo repeated transient brightenings are associated with separators that have enhanced free energy. In contrast, we find one case of an isolated transient brightening that seems to be associated with separators with a smaller free energy.

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미생물(微生物)에 의(依)한 Carotenoid색소(色素) 생성(生成)에 관(關)한 연구(硏究) [제1보(第1報)] - Rhodotorula glutinis var. glutinis sw-17의 Carotenid생성(生成)에 관(關)하여 - (Studies on the Production of Carotenoid Pigments by Microorganism [Part I] - The Carotenoid Production in Rhodotorula glutinis var. glutinis Sw-17 -)

  • 박기현;박성오
    • Applied Biological Chemistry
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    • 제19권4호
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    • pp.243-247
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    • 1976
  • 토양(土壤)으로부터 분리동정(分離同定)된 우수(優秀)한 세포내(細胞內) 지질생성균주(脂質生成菌株)인 Rhodotorula glutinis var. glutinis sw-17에 대(對)하여 carotenoid생성능(生成能)을 검토(檢討)하고서 이 균주(菌株)를 $25^{\circ}C$에서 8일간(日間) 진환배양(振還培養)하여 caroteneid 색소(色素)를 추출분리(抽出分離)하여 column에 흡착(吸着)된 색소층(色素層)의 순서(順序)와 용출(溶出)하여 정제(精製)한 각색소(各色素)의 흡수곡선(吸收曲線)에 의하여 각각(各各)의 carotenoid를 확인(確認)했으며 이들의 흡광도(吸光度)를 측정(測定)하여 Beer의 법칙(法則)에 따라 참고문헌(參考文獻)의 흡광계수(吸光係數)를 사용(使用)하여 정량(定量)한 결과(結果) torularhodin 25.52%, torulene 38.16%, neuroporene 1.49%, ${\gamma}-carotene$ 9.88%, ${\beta}-zeacarotene$ 2.0%, ${\beta}-carotene$ 19.95%이었으며 ${\delta}-carotene$은 거의 흔적(痕蹟)에 가까웠다. 따라서 Rhodotonula glutinis var. glutinis sw-17의 주색소(主色素)는 torularhodin, torulene이었다.

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Photopic과 Scotopic 곡선의 분포함수 유도 및 분석 (A Distribution Function Analysis of Photopic and Scotopic Curves)

  • 김용근
    • 한국안광학회지
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    • 제5권2호
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    • pp.157-161
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    • 2000
  • 광원의 세기가 다른 조건하에서 눈의 시감효율은 추상체와 간상체에 의해 파장에 따라 2개의 함수로 이루어진다. 광자에 대한 추상체-간상체의 반응확률을 이용하여 $P({\lambda})=A{\cdot}e^{-({\lambda}-{\lambda}_0)^2/2W^2}$의 분포함수 수식을 유도하였다. 이 식은 파장에 따른 CIE의 눈의 시감효율 곡선에 잘 적용되며 상대 시감효율의 경우 photopic의 경우 A=106.4, ${\lambda}_0=559.2$, W=83.5이고 scotopic의 경우 A=99.3, ${\lambda}_0=502.6$, W=79.5의 값을 얻었다. 1m/W의 단위를 사용하는 시감효능 곡선에서는 photopic의 경우 $A=7.2{\times}10^4$, ${\lambda}_0=559.2$, W=86.5이고 scotopic의 경우 $A=1.6{\times}10^5$, ${\lambda}_0=502.6$, W=79.5의 값을 얻었다.

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