• Title/Summary/Keyword: photometric method

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A Comparative Study of Primary Production by using the $^{14}C$ and Oxygen Methods ($^{14}C$ - 법과 산소법에 의한 일차생산 비교연구)

  • 심재호;강성현
    • 한국해양학회지
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    • v.21 no.2
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    • pp.73-84
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    • 1986
  • Photometric Winkler titration provides high precision enough to use the oxygen method in moderately productive waters In short incubation (2-4hr), about $2{\mu\textrm{g}}C/\ell/h$ can be differentiated by the photometric titration. The oxygen and $^{14}C$ methods resulted in good agreement with each other in the diurnal primary production measurements. Despite small descrepancies the severe underestimation of $^{14}C-technique$ was not observed in short-term incubation. Size-fractionated production studies indicated the importance of nanoplanktonic production in the coastal water (62-88%). Bacterial respiration may lead to significant underestimation in estimating net photosynthesis in the oxygen method. In spite of some problems associated with the ecological application of antibiotics, it seems feasible to use Gentamycin in separating planktonic respiration from that of total community.

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A Study on the Strategies of the Positioning of a Satellite on Observed Images by the Astronomical Telescope and the Observation and Initial Orbit Determination of Unidentified Space Objects

  • Choi, Jin;Jo, Jung-Hyun;Choi, Young-Jun;Cho, Gi-In;Kim, Jae-Hyuk;Bae, Young-Ho;Yim, Hong-Suh;Moon, Hong-Kyu;Park, Jang-Hyun
    • Journal of Astronomy and Space Sciences
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    • v.28 no.4
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    • pp.333-344
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    • 2011
  • An optical tracking system has advantages for observing geostationary earth orbit (GEO) satellites relatively over other types of observation system. Regular surveying for unidentified space objects with the optical tracking system can be an early warning tool for the safety of five Korean active GEO satellites. Two strategies of positioning on the observed image of Communication, Ocean and Meteorological Satellite 1 are tested and compared. Photometric method has a half root mean square error against streak method. Also eccentricity method for initial orbit determination (IOD) is tested with simulation data and real observation data. Under 10 minutes observation time interval, eccentricity method shows relatively better IOD results than the other time interval. For follow-up observation of unidentified space objects, at least two consecutive observations are needed in 5 minutes to determine orbit for geosynchronous orbit space objects.

PHOTOMETRIC AND RADIAL VELOCITY CURVES ANALYSES OF THE TRIPLE SYSTEM $\lambda$ TAURI (삼중성 $\lambda$ TAURI의 광도곡선 분석과 시선속도의 분석)

  • 이용삼;권수진
    • Journal of Astronomy and Space Sciences
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    • v.12 no.1
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    • pp.30-43
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    • 1995
  • New UBVRI observations of triple star $\lambda$ Tau were made at Chungbuk Ntional University Observatory for 31 nights from Dec. 1990 to Jan. 1994. A total of 2930 photometric observations were obtained with 586 points for each filters, and BVRI light curves were constructed. From the primary light curves, the one times of primary minimum light was determined with a new light element. The photometric solutions of light curves for $\lambda$ Tau were calculated by using Wilson-Devinney method with our BVRI light curves and the BV light curves obtained by Grant(1959). We determined spectroscopic solutions that were satisfied with these two light curves and the radial velocity curves had been collected by Fekel and Tomkin (1982). From these values, absolute dimensions for this system were estimated. The radius and mass for the primary star are turned out to be $8.3R_\odot$ and $8.1m_\odot$, and $6.5R_\odot$ and $2.1m_\odot$ for the secondary star, respectively.

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ABSOLUTE DIMENSIONS OF CONTACT BINARY STARS IN BAADE WINDOW (바데의 창 영역에서 발견된 접촉형 쌍성의 절대량)

  • 강영운
    • Journal of Astronomy and Space Sciences
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    • v.16 no.2
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    • pp.217-266
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    • 1999
  • The light curves of the representative 6 contact binary stars observed by OGLE Project of searching for dark matter in our Galaxy have been analyzed by the method of the Wilson and Devinney Differential Correction to find photometric solutions. The orbital inclinations of these Devinney Differential Correction to find photometric solutions. The orbital inclinations of these binaries are in the range of $52^{circ}-69^{\circ}$ which is lower than that of the solar neighborhood binaries. The Roche lobe filling factor of these binaries are distributed in large range of 0.12 - 0.90. Since absence of spectroscopic observations for these binaries we have found masses of the 6 binary systems based on the intersection between Kepler locus and locus derived from Vandenberg isochrones in the mass - luminosity plane. Then absolute dimensions and distances have been found by combining the masses and the photometric solutions. The distances of the 6 binary systems are distributed in the range of 1 kpc- 6 kpc. This distance range is the limiting range where the contact binaries which have period shorter than a day are visible. Most contact binaries discovered in the Baade window do not belong to the Galactic bulge.

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Quality Assessment of Images Projected Using Multiple Projectors

  • Kakli, Muhammad Umer;Qureshi, Hassaan Saadat;Khan, Muhammad Murtaza;Hafiz, Rehan;Cho, Yongju;Park, Unsang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.6
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    • pp.2230-2250
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    • 2015
  • Multiple projectors with partially overlapping regions can be used to project a seamless image on a large projection surface. With the advent of high-resolution photography, such systems are gaining popularity. Experts set up such projection systems by subjectively identifying the types of errors induced by the system in the projected images and rectifying them by optimizing (correcting) the parameters associated with the system. This requires substantial time and effort, thus making it difficult to set up such systems. Moreover, comparing the performance of different multi-projector display (MPD) systems becomes difficult because of the subjective nature of evaluation. In this work, we present a framework to quantitatively determine the quality of an MPD system and any image projected using such a system. We have divided the quality assessment into geometric and photometric qualities. For geometric quality assessment, we use Feature Similarity Index (FSIM) and distance-based Scale Invariant Feature Transform (SIFT). For photometric quality assessment, we propose to use a measure incorporating Spectral Angle Mapper (SAM), Intensity Magnitude Ratio (IMR) and Perceptual Color Difference (ΔE). We have tested the proposed framework and demonstrated that it provides an acceptable method for both quantitative evaluation of MPD systems and estimation of the perceptual quality of any image projected by them.

A Study on the Analysis of Components in Foam Produced from a Stream (하천 발생 거품의 성분에 관한 분석 연구)

  • Bae, Jang-Soon;Park, Chan-Kyo;Sung, Ki-Chun;Lee, Seok-Woo;Hwang, Yong-Hyun
    • Journal of the Korean Applied Science and Technology
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    • v.21 no.2
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    • pp.117-123
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    • 2004
  • According to increase of using quantity, people interested in the environmental influence by synthetic detergent. The main visible form when synthetic detergent dissolved in water is generating foams. This foam makes coating over water surface and prevents oxygen penetrating in water and make water more polluted with that result. To analyze, components and origins of the foam, and to make clear its environmental influence in this study. The analyzing objects are introducing water of sewage treatment plant from the a tributary to the Han River. After analysis, reached the conclusion like below, Analyzing foams and introducing water by sublation method, average return rate of standard LAS (1.0ppm) is 90%. LAS contents of foams analyzed by UV photometric method and HPLC method are 35.0ppm and 44.5ppm each, and AOS contents of foams analyzed by the same method are 0.6ppm and 0.4ppm each. We can find out by this study's analyzing results that the main components of foams are anion surfactant, it's content and in case of capric acid linoleic acid, it's contents.

SEARCHING MINOR PLANETS AND PHOTOMETRIC QUALITY OF 60cm REFLECTOR IN GIMHAE ASTRONOMICAL OBSERVATORY (김해천문대 60cm 반사망원경의 측광성능 분석과 소행성 탐사)

  • Lee, Sang-Hyun;Kang, Yong-Woo;Lee, Kyung-Hoon
    • Journal of Astronomy and Space Sciences
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    • v.24 no.3
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    • pp.209-218
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    • 2007
  • In this paper, we have presented the observational result for the photometric quality of main telescopes in Gimhae Astronomical Observatory. Also we performed the observation of searching new minor planets as competitive work in public observatories. The observation was carried out using 60cm telescope of Gimhae Astronomical Observatory on 2007 January 13. And, $Sch\ddot{u}ler$ BVI filters and 1K CCD camera (AP8p) were used. To define the quality of CCD photometry, we observed the region of well-known standard stars in the open cluster M67. From observed data, The transformation coefficients and airmass coefficients were obtained, and the accuracy of CCD photometry was investigated. From PSF photometry, we obtained the color-magnitude diagram of M67, and considered the useful magnitude limit and the physical properties of M67. This method can be successfully used to confirm the photometric quality of main telescope in public observatories. To investigate the detection possibility of unknown object as astroid, we observed the near area of the opposition in the ecliptic plane. And we discussed the result. Our result show that it can be possible to detect minor planets in solar system brighter than $V{\sim}18.3mag$. and it can carry out photometric study brighter than V 16mag. in Gimhae Astronomical Observatory. These results imply that the public observatories can make the research work.

CCD PHOTOMETRY OF CONTACT BINARY WZ Cephei (접촉쌍성 WZ Cephei의 CCD 측광관측)

  • Lee, Woo-Baik;Kang, Young-Woon;Oh, Kyu-Dong
    • Journal of Astronomy and Space Sciences
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    • v.25 no.1
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    • pp.19-24
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    • 2008
  • We present the full BVR light curves and five times of minima of WZ Cep to provides a complete photometric solution and to confirm the long term variation of the light curves. Our light curves show symmetry while previous light curves of Hoffmann (1984) show a high degree of asymmetry (the O'Connell effect). The BVR light curves were analyzed by the method of Wilson-Devinney Differential Correction. Our photometric results show a good agreement with those of Djurasevic et al. (1998).