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        검색결과 213

        101.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Many departments in the governmental organization including Ministry of Science & Technology (MOST) allocate some of their budget into research and development in astronomy and space science. We identify the research projects related to astronomy and space science that were funded by the government during fiscal years 2004-2005. Then the distribution of budgets of those projects is analyzed according to several classification schemes and characteristics in order to find out the status and trends of the investment in this field. Five departments had conducted more than 190 projects related to astronomy and space science, which accounted for 7.3% of the government R&D budget in space and aeronautics area. As for most fields of basic science, MOST and Ministry of Education & Human Resources Development invested the most of budget in astronomy related projects. We briefly discuss the implications of this study.
        4,000원
        102.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, we analyze the scientific inquiries type on Almanac and Historical Astronomy asked through the Q&A service in Korea Astronomy and Science Institute(KASI) webpage with the aid of scientific inquiries analysis methods. We also study the contents of the questions. Specifically, we have created statistics of questions and inquiries, and have developed categories to analyze the characteristics of questions with regard to their cognitive aspects. Each question is categorized as either of the two elements based on their recognitive aspect: science knowledge or science study. Each element also has sub-categories that help the reader understand the characteristics of the questions. For the analysis, we used the sample consisting of questions collected from April, 2005 to June, 2007. Through this study, we achieved a better understanding of the questions in the area of Almanac and Historical Astronomy asked in the Q&A service. Throughout this study, we find that the need of questions in the area of Almanac and Historical Astronomy are increasing with time, and the overall quality of the questions is getting improved. As we expect that the number of people using our Q&A service will increase and that the questions will get more difficult to answer, development of improved contents is required.
        4,000원
        103.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have been making dual dome enclosures which are useful to track artificial space objects at SSNT (Space Science and Technology Lab.) Kyung Hee University. We verified the safety of the dome enclosures using basic design and structure analyses before manufacturing them, and then performed an optimization analysis for economic and safe systems. The dome enclosure has a fully-open type structure to smoothly operate a telescope made in the style of altazimuth mount with very fast tracking. It is also designed to be safe against extreme weather conditions. The general structure of the observatory system consists of the dual dome enclosures at the top of a container. For the structural analyses, we consider the following two methods: (1) gravitational sustain analysis - how the structure supporting the dome withstand the weight of the dome, and (2) wind load analysis that considers the effect of the wind velocity at the region where the observatory is located. The result of overall deformation is found to be less than 0.551mm and the result of equivalent stress is found to be 20.293Mpa, indicating that the dual dome system is reasonably designed. This means structurally to be safe.
        4,000원
        104.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, we describe the proposed KVN (Korean VLBI Network) clock system in order to make the observation of the VLBI effectively. In general, the GPS system is widely used for the time information in the single dish observation. In the case of VLBI observation, a very high precise frequency standard is needed to perform the observation in accordance with the observation frequency using the radio telescope with over 100km distance. The objective of the high precise clock system is to insert the time-tagging information to the observed data and to synchronize it with the same clock in overall equipments which used in station. The AHM (Active Hydrogen Maser) and clock system are basically used as a frequency standard equipments at VLBI station. This system is also adopted in KVN. The proposed KVN clock system at each station consists of the AHM, GPS time comparator, standard clock system, time distributor, and frequency standard distributor. The basic experiments were performed to check the AHM system specification and to verify the effectiveness of implemented KVN clock system. In this paper, we briefly introduce the KVN clock system configuration and experimental results.
        4,200원
        105.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We present the sensitivity calculation results for observing the Cosmic Infrared Background (CIRB) by the Multi-purpose IR Imaging System (MIRIS), which will be launched in 2010 as a main payload of the Science and Technology Satellite 3 (STSAT-3). MIRIS will observe in I ( 0.9∼1.2um) and H (1.2∼2.0um) band with a 4×4 degree field of view to obtain the large scale structure ( ∼3 degree) of the CIRB. With the given specifications of the MIRIS, our sensitivity calculation results show that the MIRIS has a detection limit of ∼9nWm−2sr−1 (I band) and ∼6nWm−2sr−1 (H band), which is appropriate to observe the large scale structure of CIRB.
        4,000원
        106.
        2007.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The international cooperation project CIBER (Cosmic Infrared Background ExpeRiment) is a rocket-borne instrument, of which the scientific goal is to measure the cosmic near-infrared extra-galactic background to search for signatures of primordial galaxy formation. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. Currently, all the subsystems have been built, and the integration, testing, and calibration of the CIBER system are on process for the scheduled launch in June 2008.
        4,000원
        111.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
          A space launch vehicle system represents a typical example of large-scale multi-disciplinary systems, consisting of subsystems such as mechanical structure, electronics, control, telecommunication, propulsion, material engineering etc. A lot of cost is
        4,000원
        112.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We designed the Intermediate Frequency(IF) distributor for multi beam backend system and manufactured Voltage to Frequency Converter(VFC) to measure the multi-beam receiver performance. Multi beam receiver has 15 channel receivers and can get 15 spectrums at once. The multi beam receiver has more observation efficiency than single beam receiver. We manufactured the 15 IF distributors to distribute IF signal for Autocorrelation spectrometer that is radio signal processor. Also, we manufactured the VF Converter to test the performance measurement of receiver for Korea VLBI Network(KVN) system which is under-construct in Seoul, Ulsan and Jeju. As a result of performance measurement, we could obtain linearity of 99.4% on the input power vs output frequency and measured the operating range of input frequency.
        4,000원
        117.
        2007.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Quasars at cosmological distances can be gravitationally lensed by galaxies into two or more images. The probability of this lensing and the angular separation between the images depend on the geometry and the expansion history of the universe as well as the lensing galaxies. The time delay between lensed images is also a direct indicator of the size of the universe. I review these cosmological applications of multiple-image gravitationally lensed quasars to determine or constrain the cosmological parameters.
        5,500원
        118.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        An alt-azimuth type mount system, developed at the Space Science and Technology Laboratory, Kyung Hee University, has been found to experience some difficulties in monitoring of the artificial space objects. Since the telescope installed on the alt-azimuth mount does not rotate on the same axis as the earth does, this mount system needs an instrument rotator to correct the field rotation. Although there are some commercial instrument rotators already in the market, those are not suitable for our system due to their low interchangeability. In this study, we have designed a new high speed instrument rotator and calculated the deformation of new designed system using structural analyses.
        4,000원
        119.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We have tested the performance of the Proto-model of Space Infrared Cryogenic System (PSICS), which is a small infrared camera, developed by Korea Astronomy and Space science Institute (KASI), Korea Basic Science Institute (KBSI), Korea Institute of Machinery and Materials (KIMM), and i3system co., as a cooperation project. The purpose of PSICS is to ensure a technology of small infrared cryogenic system for future development of space infrared (IR) cameras. PSICS consists of cryogenic part, IR sensor and electronics part, and optical part. The performance test of each part and the integrated system has been completed successfully. PSICS will be used as a guiding camera for ground-based IR telescopes and a test system for developing a space-borne instrument.
        4,000원
        120.
        2006.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        A Korean team (Korea Astronomy and Space Science Institute, Korea Basic Science Institute, and Kyung Hee University) takes part in an international cooperation project called CIBER (Cosmic Infrared Background ExpeRiment), which has begun with Jet Propulsion Laboratory (JPL) in USA and Institute of Space and Astronautical Science (ISAS) in Japan. CIBER is a rocket-borne instrument, of which the scientific goal is to measure the cosmic near-infrared extra-galactic background to search for signatures of primordial galaxy formation. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. The Korean team is in charge of the ground support electronics and manufacturing of optical parts of the narrow-band spectrometer, which will provide excellent opportunities for science and technology to Korean infrared groups.
        4,000원