• Title/Summary/Keyword: two-color diagram

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ANALYZING ISUAL SPECTROPHOTOMETER DATA USING A TWO-COLOR DIAGRAM METHOD

  • CHEN ALFRED BING-CHIH;CHIANG PO-SHIH;HUANG TIAN-HSIANG;KUO CHENG-LING;WANG SHI-CHUN;SU HAN-TZONG;HSU RUE-RoN;CHANG MING-HUI;CHANG YEOU-SHIN;LIU TIE-YUE;MENDE STEPHEN B.;FREY HARALD U.;FUKUNISHI HIROSHI
    • Journal of The Korean Astronomical Society
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    • v.38 no.2
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    • pp.303-306
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    • 2005
  • Transient luminous events (TLEs; sprites, elves, jets and etc.) are lightning-related optical flashes occurring above thunderstorms. Since the first discovery of sprites in 1989, scientists have learned a great deal about the morphological, spectroscopic and electromagnetic characteristics of TLEs through ground and spacecraft campaigns. However, most of the TLE studies were based on events recorded over US High Plains. To elucidate the possible biasing effects, space-borne observations are needed and have their merits. Imager of sprites and Upper Atmospheric Lightning (ISUAL) on the FORMOSAT-2 satellite is the first instrument to carry out a true global measurement of TLEs from a low- earth orbit. In this short paper, we apply a common astronomical data analysis technique, two-color diagram, on the ISUAL spectrophotometer (SP) data. By choosing appropriated bandpasses and converting the measured flux of TLEs into the unit of magnitude, two-color diagrams of TLEs can be constructed. We demonstrate that two-color diagrams, which were constructed from the narrow-band spectrophotometer data, can be used to classify different types of TLEs and trace their temporal evolution. The amount of reddening due to Earth's atmosphere can also be estimated from two-color diagrams assembled from the broad-band spectrophotometer data.

INFRARED PHOTOMETRIC STUDY OF FIELD POPULATION II STARS

  • LEE SANG-GAK;BRUCE W. CARNEY;ROBERT PROBST
    • Journal of The Korean Astronomical Society
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    • v.30 no.1
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    • pp.1-11
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    • 1997
  • Near infrared JHK magnitudes are presented for two hundred two high proper motion stars. We have observed high proper motion stars in the near-infrared bands(JHK) using the COB detector on the Kitt Peak 1.3m, 2.1m and 4m telescopes. The observations and data reduction procedures are described. The infrared color magnitude diagram and color-color diagrams for the program stars are presented.

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Selection of Apple Ground Color for Maturity Index Using Color Machine Vision (컬러 컴퓨터 시각에 의한 사과 선별 기준색깔 선정)

  • 서상룡;성제훈
    • Journal of Biosystems Engineering
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    • v.22 no.2
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    • pp.210-216
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    • 1997
  • A study to select ground colors of Fuji apple for maturity index which are needed to standardize grading of the apples is presented. Two extreme colors of immature and fully mature Fuji and Zonagold apples produced in Korea were determined. Various ground colors of Fuji apple between the two extreme colors were collected and classified by human vision and colors of Fuji apple for maturity index were selected from the classification. Coordinates of the selected colors in xy chromaticity diagram were determined by spectrophotometers to define them in a standard coordinate system. Coordinates of the colors in r-g chromaticity diagram using a color machine vision system were also determined to use the colors in apple grading by the machine vision system. Grading Fuji apples using the machine vision system was performed and result of the grading was compared with Ending results of human vision and colorimeter. The comparison was performed with the same Fuji apple samples and showed 65% md 75% of same grades, respectively, as the grades determined by the machine vision system. Differences of fading performance between the compared three grading methods were explained as mainly because of the differences of observation area of the grading methods.

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The evaluation of curtain design by simulation method (시뮬레이션을 이용한 커튼 디자인의 평가)

  • 장서윤
    • Journal of the Korean Home Economics Association
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    • v.33 no.5
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    • pp.167-176
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    • 1995
  • This study is to present various curtain design by simulating method of the 32 case's combination of the styles, the patterns, the colors of curtain design for 50 woman collage students by photo shop program. The major findings of this study can be summarized as follow : The evaluation factors of curtains design was classified into three groups ; emotionality, harmoniousness, stimulus. The best choice to emphasize the atmosphere for "emotionality" of the first factor is curtain with the valance of cloud style, mixed Diagram pattern and ivory color(NO.16). The best choice to emphasize the atmosphere for "harmoniousness" as well as "stimulus" is curtain with the valance of two pieces cloud style, flower pattern and pink color(NO.18). The best choice to emphasize the atmosphere for "emotionality" and "stimulus" as well as "emotionality" and "harmoniousness" is curtain with the valance of natural fold style, stripes pattern and pink color(NO.6). The best choice to emphasize the atmosphere for "harmoney" and "stimulus" is curtain with the valance of two pieces cloud style, flower pattern and pink color(NO.18). The best choice to emphasize the atmosphere for "emotionality", "harmoniousness" and "stimulus" is curtain with the valance of two pieces cloud style, flower pattern and pink color(NO.18).

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Multiple Stellar Populations of Galactic Globular Clusters NGC 6656 and NGC 6723

  • Chun, Sang-Hyun;Sohn, Young-Jong;Lee, Young-Wook;Han, Sang-Il;Roh, Dong-Goo;Lee, Jae-Woo
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.143.1-143.1
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    • 2011
  • Deep Ca,b,y images obtained from the CTIO 4m Blaco telescope are used to investigate the multiple stellar populations of red giant branch (RGB) and sub-giant branch (SGB) in Galactic globular clusters NGC 6656 and NGC 6723. For NGC 6656, confirming the result of Lee et al. (2009), we find two discrete populations of the RGB stars of which mean color separation is about 0.2 mag in hk[=(Ca-b)-(b-y)] index. Furthermore, we also find the bimodel distribution of the SGB stars in (hk, y) color-magnitude diagram. A new finding is that the (hk, y) color-magnitude diagram of NGC 6723 shows two distinct RGB stars with different calcium abundances of which mean color separation is about 0.12 mag in hk index. This multiple stellar feature has not been observed in previous observation, suggesting that NGC 6723 may also be a possible relic of dwarf galaxies that merged into the Milky Way in the past. Thus our result adds further constraints to the merging scenario of the Galaxy formation. Unfortunately, the split of SGB stars in NGC 6723 is not obvious. We will present some statistical results to compare properties of two populations in two clusters.

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INFRARED AND HARD X-RAY DIAGNOSTICS OF AGN IDENTIFICATION FROM THE AKARI AND SWIFT/BAT ALL-SKY SURVEYS

  • Matsuta, K.;Gandhi, P.;Dotani, T.;Nakagawa, T.;Isobe, N.;Ueda, Y.;Ichikawa, K.;Terashima, Y.;Oyabu, S.;Yamamura, I.;Stawarz, L.
    • Publications of The Korean Astronomical Society
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    • v.27 no.4
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    • pp.285-286
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    • 2012
  • We combine data from two all-sky surveys, the Swift/Burst Alert Telescope 22 Month Source Catalog and the AKARI Point Source Catalogue, in order to study the connection between the hard X-ray (> 10 keV) and infrared (IR) properties of local active galactic nuclei (AGN). We find two photometric diagnostics are useful for source classification: one is the X-ray luminosity vs. IR color diagram, in which type 1 radio-loud AGN are well isolated from other AGN. The second one uses the X-ray vs. IR color-color diagram as a redshift-independent indicator for identifying Compton-thick (CT) AGN. Importantly, CT AGN and starburst galaxies in composite systems can also be separated in this plane based upon their hard X-ray fluxes and dust temperatures. This diagram may be useful as a new indicator to classify objects in new surveys such as with WISE and NuSTAR.

Iridescent Specular Structural Colors of Two-Dimensional Periodic Diffraction Gratings

  • Yoon, Kyungsik;Choi, Sujin;Paek, Jeongyeup;Im, Dajeong;Roh, Jinyoung;Kwon, Jaebum;Kim, Hwi
    • Journal of the Optical Society of Korea
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    • v.18 no.5
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    • pp.616-622
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    • 2014
  • Specular structural colors generated by two-dimensional periodic binary gratings are investigated theoretically. An approximate mathematical model of the grating specular structural colors is described, based on scalar nonparaxial diffraction theory, and the functional relationships of specular structural color and structural parameters of gratings are analyzed. Through this, the optimal condition for maximizing the color-representation range in the standard CIE 1931 chromaticity diagram is derived.

Effects of Current Modulation Conditions on the Chromaticity of Phosphor Converted (PC) White LEDs

  • Kim, Seungtaek;Kim, Jongseok;Kim, Hyungtae;Kim, Yong-Kweon
    • Journal of the Optical Society of Korea
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    • v.16 no.4
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    • pp.449-456
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    • 2012
  • For two well-known modulation methods, stepwise current modulation (SCM) and pulse width modulation (PWM), the effects of driving current modulation conditions on chromaticity were experimentally investigated in a white LED lighting system. For the experimental implementation of both SCM and PWM, a white LED lighting was fabricated using phosphor converted (PC) white light emitting diodes (LEDs) and a driving circuit module was developed. By using them, the variations of illuminance, color coordinates, and spectrum were evaluated under various forward current conditions. Through the analysis in color coordinates, yellow shift in SCM and blue shift in PWM were observed on chromaticity diagrams with increasing average driving current. In addition, in order to analyze color deviation quantitatively, color distance before and after current increase, and the correlated color temperature (CCT) were calculated. As a result, for the white LED lighting in both modulation conditions, the maximum difference in the calculated CCT was obtained close to 1000 K. It means that careful consideration is required to be taken in the design of illumination systems to avoid serious problems such industrial accidents.

Geochronology and Petrogenetic processes of the so-called Hongjesa granite in the Seogpo-Deogku Area (석포(石浦)-덕구간(德邱間)에 분포(分布)하는 소위(所謂) 홍제사화강암(洪濟寺花崗岩)의 지질연대(地質年代)와 생성과정(生成過程)에 대(對)한 硏究(연구))

  • Kim, Yong Jun;Lee, Dai Sung
    • Economic and Environmental Geology
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    • v.16 no.3
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    • pp.163-221
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    • 1983
  • Main aspects of this study are to clarify geochronology and petrogenetic processes of the so-called Hongjesa granite, which is a member of various intrusive rocks exposed in the northeastern part of the Ryongnam Massif, one of the Precambrian basements of South Korea. In this study, the Hongjesa grainte is divided into four rock units based on the geologic age, mineralogical and chemical constituents, and texture: the Precambrian Hongjesa granite gneiss (Hongjesa granite Proper) and leucogranite gneiss, the Paleozoic gnessic two mica granite, and the Jurassic muscovite granite. The Hongjesa granite gneiss is identified by its grayish color, slight foliation, and porphyroblastic texture. The leucogranite gneiss is distinct by its light gray color, sand medium to coarse grained texture. The gneissic two mica granite is distinguished from others by its strong foliation, containing gray-colored feldspar phenocrysts with biotite and muscovite in varying amounts. The muscovite granite occurs as a small stock containing feldspar phenocrysts along margin of the stock. These granitic rocks vary widely in composition, reflecting the facts that they partly include highly metamorphosed xenolith and schlierens as relics of magmatic and anatectic processes. In particular, grayish porphyroblasts of microcline perthite is characteristic of the Hongjesa granite gneiss, whereas epidote and garnet occur in both the Hongjesa granite gneiss and leucogranite gneiss. These minerals are considered to be formed by potassic metasomatism and contamination of highly metamorphosed rocks deeply buried under the level of the Hongjesa granite emplacement. The individual synchronous granitic rocks plotted on Harker diagram show mostly similar trends to the Daly's values. The plots of the Hongjesa granite gneiss and gneissic two mica granite concentrate near the end part of the calc-alkalic rock series on the AMF diagrams, whereas those of the leucogranite gneiss and muscovite granite indicate the trend of the Skaergaard pluton. These granitic rocks plotted on a Q-Ab-Or diagram (petrogeny's residua system) fall well outside the trough of the system. This can be attributed to the potassic matasomatism of these rocks. On the ACF diagram, these rocks appear to be dominantly I-type prevailing over S-type. The K-Ar ages, obtained from a total of 7 samples of the leucogranite gneiss, gneissic two mica granite, muscovite granite, porphyritic alkali granite, and rhyolitic rock, in addition to the Rb/Sr ages of the Hongjesa granite gneiss by previous workers, permit the rock units to be arranged in the following chronological order: The middle Proterozoic Hongjesa granite gneiss (1714-1825 m.y.), the upper proterozoic leucogranite gneiss (875-880 m. y.), the middle Paleozoic gneissic two mica granite (384 m. y.) the upper Jurassic muscovite granite (147 m. y.), the Eocene alkali granite (52 m. y.), and the Eocene rhyolitic rock (45 m. y.). From the facts and data mentioned above, it is concluded that the so-called Hongjesa granite is not a single granitic mass but is further subdivided into the four rock units. The Hongjesa granite gneis, leucogranite gneiss, and gneissic two mica granite are postulated to be either magmatic or parautochtonous, intrusive, and the later muscovite granite is to be magmatic in origion.

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A Study on the Traditional Forged High Tin Bronzes and the Rivet Joints in Korea (한국의 전통 방짜유기와 이에 사용된 리벳에 관한 연구)

  • Lee, Jae Sung;Kim, Won Soo;Park, Jang Sik
    • Korean Journal of Metals and Materials
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    • v.46 no.1
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    • pp.26-32
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    • 2008
  • Examination of two bronze vessels supposedly from the Koryo dynasty revealed that they consist of bowls and stands that are fixed together using rivet joints made of Cu-Ag alloys. The bowls and stands were forged out of unleaded bronze alloys of approximately 22 weight % Sn before being quenched from the ${\alpha}+{\beta}$ region of the Cu-Sn phase diagram. This specific alloy and the thermo-mechanical treatment constitute two key elements of the unique technical tradition called Bangcha (방짜) that has long been established in Korea. The high Sn content ensures better casting and the thermal treatment causes the brittle ${\delta}$ phase to be avoided in forging as well as in services. The experiment on the laboratory Cu-Ag alloys of varying Ag contents suggested that the Cu-Ag system was the best choice of materials for the rivets at the time in view of their color, availability, ductility and low melting points.