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        검색결과 42

        21.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We obtained three-color composite. images of 78 celestial objects most of which are listed in Messier catalogue. In order to make color images, 118 raw image sets were taken with B, V, R, I and H-alpha filters. We used the 2k CCD camera attached to the 1.8 m telescope of Bohyunsan Optical Astronomy Observatory. These composite images are to be used for educational purposes or public releases. The images are presented on the website, http://www.boao.re.kr/-ybjeon/boao_images.htrnl.
        4,000원
        22.
        2001.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We tested the characteristics of the BOAO Medium Dispersion Spectrograph (MDS) such as the CCD capabilities, wavelength shift by gravity direction variation, slit illumination function and efficiency. Then we calculated the appropriate exposure time to obtain the given S/N ratio for several given magnitudes. Also the remaining problems to be improved were discussed.
        4,000원
        25.
        2000.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The BOES (BOAO Echelle Spectrograph), a fiber-fed echelle spectrograph of the BOAO 1.8 m telescope, has been designed and now is being manufactured. The BOES follows a white pupil design collimated with two off-axis parabolic mirrors. The 136mm collimating beam leaving the 41.59 grooves/mm R4 echelle grating is refocused near the narrow folding mirror. Through the two cross-disperser prisms and ϕ250mm(f/1.5) ϕ250mm(f/1.5) transmission camera, the beam images on EEV 2k×4k 2k×4k CCD. The BOES can take the wavelength range of 3700 to 10100Å at a single spot with spectral resolution R = 20000 to 40000 depending on the fiber set employed. We describe the key sciences and performance, current status of construction, and future plan of the BOES.
        4,000원
        26.
        1999.10 구독 인증기관·개인회원 무료
        27.
        1998.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We installed windscreen at the BOAO 1.8m telescope dome, in order to reduce the degradation of image Quality under strong wind larger than 8m/sec. The windscreen was designed on the basis of that installed at the MSSSO 2.3m telescope dome in Australia. We developed control system (remote control and user program) of the windscreen, being able to operate the windscreen at observation room. We tested the performance of the windscreen under strong wind of 6-15m/see. Tracking error of the telescope, especially in altitude-axis, was greatly decreased when the windscreen was used. Standard deviation of the error was estimated to be less than 0.3arcsec, which has little effect on image quality.
        4,000원
        28.
        1998.10 구독 인증기관·개인회원 무료
        31.
        1997.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Detailed low spectral resolution observations of the spectrum have been made for three early spectral type standard stars, HR718, HR1544, HR3454, respectively, for the wavelength region 4,300 A to 7,500 A, using the Bohyunsan Optical Astronomy Observatory (BOAO) Middle- Dispersion Spectrograph. These standard stars were chosen from well-known bright northern standard stars. All of the observed long slit spectral data has been reduced and analyzed using the IRAF reduction procedure. The derived extinction coefficients are compared with the other observatory result. The derived value can be used in the determination of flux calibration of BOAO spectroscopic observation. However, until the high quality data are secured from a new series of observation in the blue region and are re-analyzed together, the extinction coefficients below the 4,000 A wavelength remains unknown.
        4,000원
        33.
        1996.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We propose the development and test result of new optical axis alignment system for the interchangeable F/8 secondary mirror of the BOAO 1.8m telescope system. Since the original system was not equipped with a suitable optical alignment facility, the whole alignment process was performed by hand. It was necessary at least three persons working more than 2 nights and the altitude of the telescope could not exceed 10 degrees, in such altitude the alignment quality was not so good by atmospheric effect. The new system adopts position readable motorized system and remote control operation by the computer installed in observation room, which reduces the number of workers to only one and eliminates the altitude restriction. The defocused CCD image pair obtained at higher altitude makes the aberration estimates more accurately and the number of required alignment loops is reduced from 10 to 4. The system has been installed on September 1, and performed alignment three times. The test results show that the system is stable and accurate, gives better optical performance of the telescope under F/8 focus. We hope to emphasize the fact that the new system will increase observation time of the telescope by about 20 nights per year assuming one alignment in every month.
        4,500원
        34.
        1996.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The development of universal CCD camera control software for all BOAO CCD camera systems is proposed. The new software, running under Sun SPARCstation and motif based X window system with SunOS 4.1.3 operating system, replaces existing control software based on NeXTstation color and NeXTstep 2.1 operating system which is no more produced now. Several new features of the new software is introduced, some of which are 1) the image contrast is enhanced by color manipulation and display, 2) image zooming and trimming, 3) any size of image can be displayed in the scrolled window, and 4) the offset between telescope pointing position and CCD center is easily calculated by alt-azi map. Along with the above new features, the new software has advantages including ease of maintenance and upgrading and elimination of risk caused by hardware damage. Since September 1, the software beta version is being used by observers and there is not seen severe problem regarding the software itself, but several requests to equip more features to the software will be mirrored to future release.
        4,800원
        36.
        1995.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An introduction to the first CCD camera system in Bohyunsan Optica1 Astronomy Observatory(CCD#l) is presented. The CCD camera adopts modular dewar design of IfA(Institute for Astronomy at Hawaii University) and SDSU(San Diego State University) general purpose CCD controller. The user interface is based on IfA design of easy-to-use QUI program running on the NeXT workstation. The characteristics of the CCD#l including Gain, Charge Transfer Efficiency, rms Read-Out Noise, Linearity and Dynamic range is tested and discussed. The CCD#l shows 6.4 electrons RON and gain of 3.49 electrons per ADU, and the optimization resulted in about 27 seconds readout time guaranteeing charge transfer efficiency of 0.99999 for both direction. Linearity test shows that non-linear coefficient is 6×10−7 6×10−7 in the range of 0 to 30,000 ADU.
        4,300원
        40.
        2015.04 KCI 등재 서비스 종료(열람 제한)
        본 연구는 경북 영천시 보현산(북위 36° 08-09’, 동경 128° 57-59’, 해발고도 1,124 m)에 자생하는 식물의 분포를 파악하 기 위해 수행되었다. 2012년 3월부터 2014년 7월까지 총 22회에 걸쳐 조사된 관속식물은 총 105과 327속 522종 11아종 48 종 8품 종 589분류군으로 정리되었다. 한국고유종으로는 13분류군, 환경부지정 법적관리 보호식물Ⅱ급이 2분류군, 적색목록식물 이 10분류군, 식물구계학적 특정식물이 5등급이 5분류군, 4등 급은 5분류군, 3등급은 16분류군, 2등급은 20분류군, 1등급은 37분류군, 귀화식물이 37분류군으로 나타났다. 용도별 구성은 식용 240분류군(40.7%), 약용 205분류군(34.8%), 관상용 62분 류군(10.5%), 목초용 213분류군(36.2%), 목재용 15분류군(2.5%), 섬유용 8분류군(1.3%), 공업용 3분류군(0.5%)으로 나타났다.
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