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        검색결과 3

        1.
        2001.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have analyzed 210 data of daily sunspot observations made during the period of January 3 to December 31 in 2000 and presented the daily relative sunspot numbers. For this work we estimated the conversion factors to derive the relative sunspot numbers: k=0.72 for the 20 cm refractor and k=0.56 for Solar Flare Telescope in KAO. During the year of 2000, our annual average of relative sunspot numbers is found to be 99.4. This number is obtained from the averaged daily number of 8.9 spot groups, in which there are about 62.5 distinct spots observed. According to the appearance of 423 spot groups, our analysis shows that the mean life time of the spot groups is about 4 day and 12.0 hours.
        4,000원
        2.
        2001.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Recently, we have set up a new digital CCD camera system, MicroMax YHS-1300 manufactured by Roper Scientific for Hα observation by Solar Flare Telescope at Bohyunsan Optical Astronomy Observatory. It has a 12 bit dynamic range, a pixel number of 1300×1030, a thermoelectric cooler, and an electric shutter. Its readout speed is about 3 frames per second and the dark current is about 0.05 e-/p/s at -10°. We have made a system performance test by confirming the system linearity, system gain, and system noise that its specification requires. We have also developed a data acquisition software which connects a digital camera con-troller to a PC and acquires Hα images via Microsoft Visual C++ 6.0 under Windows 98. Comparisons of high quality Hα images of AR 9169 and AR 9283 obtained from SOFT with the corresponding images from Learmonth Solar Observatory in Australia confirm that our Hα digital observational system is performed properly. Finally, we present a set of Hα images taken from a two ribbon flare occurred in AR 9283.
        4,000원
        3.
        2000.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have developed a near real-time flare alerting system which (1) downloads the latest GOES-l0 1-8 Å X-ray flux 1-min data by an automated ftp program and shell scripts, (2) produces a beep sound in a simple IDL widget program when the flux is larger than a critical value, and (3) makes it possible to do a wireless alerting by a set of portable transceivers. Thanks to the system, we have made successful Ha flare observations by the Solar Flare Telescope in Bohyunsan Optical Astronomy Observatory. This system is expected to be helpful for ground-based flare observers.
        3,000원