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        검색결과 62

        44.
        1994.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        배추좀나방과 담배거세미나방 유충에 대한 30종 한방 식물체 메탄올 조추출몰의 살충활성 및 섭식 저해활성을 잎침지법을 이용하여 5,000ppm으로 검정하였다. 황련의 추출물은배추좀나방에 대해 살충작용을 보였다. 길경, 사삼, 세신, 오배자 및 자초의 추출물은 배추좀나방 유충에 대해, 목통 및 속새의 추출물은 담배거세미나방 유충에 대한 강한 섭식저해활성을 보였으나, 오배자와 황련의 추출물은 이들 나비목 유충 모두에 강한 섭식저해활성을 나타내었다.
        4,000원
        45.
        1994.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        슈퍼요소를 이용한 구조해석은 항공기나 선박 둥 대형구조물의 해석에서 장점올 가지며 하드웨어의 제한된 조건속에서 효과적인 결과를 준다. 본 논문에서는 고정된 타이벡 (tie back) 상태에서 세계 최대의 5α삐톤, 회전 상태에서 3α%톤올 들어 올릴 수 있는 크레인선의 구조 안전성 검토를 위하여 슈퍼요소로 분할된 부분 구조물 해석을 다루었으며, 효과적인 부분구조화 (substructuring) 과정과 독특한 하중추출방법 및 유한요소 모델링 기법을 제시하고 있다. 또한 해 석결과에 근거한 실질적인 구조물의 총괄적 국부보강방법올 보여주고 있다. 대형 크레인선의 구조해석적용 연구를 통하여 부분구조기법의 효율성을 확립하였으며 이러한 해석기법을 통하여 새로운 형태의 유사한 구조물에 대한 해석지침을 제시하고 었다.
        4,000원
        51.
        2020.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The Korean Institute of Technology Satellite (KITSAT-1) is the first satellite developed by the Satellite Technology Research Center and the University of Surrey. KITSAT-1 is orbiting the Earth’s orbit as space debris with a 1,320 km altitude after the planned mission. Due to its relatively small size and altitude, tracking the KITSAT-1 was a difficult task. In this research, we analyzed the tracking results of KITSAT-1 for one year using the Midland Space Radar (MSR) in Texas and the Poker Flat Incoherent Scatter Radar (PFISR) in Alaska operated by LeoLabs, Inc. The tracking results were analyzed on a weekly basis for MSR and PFISR. The observation was conducted by using both stations at an average frequency of 10 times per week. The overall corrected range measurements for MSR and PFISR by LeoLabs were under 50 m and 25 m, respectively. The ionospheric delay, the dominant error source, was confirmed with the International Reference of Ionosphere-16 model and Global Navigation Satellite System data. The weekly basis orbit determination results were compared with two-line element data. The comparison results were used to confirm the orbital consistency of the estimated orbits.
        52.
        2019.03 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The Optical Wide-field patroL-Network (OWL-Net) is a global optical network for Space Situational Awareness in Korea. The primary operational goal of the OWL-Net is to track Low Earth Orbit (LEO) satellites operated by Korea and to monitor the Geostationary Earth Orbit (GEO) region near the Korean peninsula. To obtain dense measurements on LEO tracking, the chopper system was adopted in the OWL-Net’s back-end system. Dozens of angle-only measurements can be obtained for a single shot with the observation mode for LEO tracking. In previous work, the reduction process of the LEO tracking data was presented, along with the mechanical specification of the back-end system of the OWL-Net. In this research, we describe an integrity assessment method of time-position matching and verification of results from real observations of LEO satellites. The change rate of the angle of each streak in the shot was checked to assess the results of the matching process. The time error due to the chopper rotation motion was corrected after re-matching of time and position. The corrected measurements were compared with the simulated observation data, which were taken from the Consolidated Prediction File from the International Laser Ranging Service. The comparison results are presented in the In-track and Cross-track frame.
        53.
        2015.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        A strategy is needed for a regional survey of geosynchronous orbits (GSOs) to monitor known space objects and detect uncataloged space objects. On the basis of the Inter-Agency Debris Committee’s recommendation regarding the protected region of geosynchronous Earth orbit (GEO), target satellites with perigee and apogee of GEO ± 200 km and various inclinations are selected for analysis. The status of the GSO region was analyzed using the satellite distribution based on the orbital characteristics in publicly available two-line element data. Natural perturbation effects cause inactive satellites to drift to two stable longitudinal points. Active satellites usually maintain the designed positions as a result of regular or irregular maneuver operations against their natural drift. To analyze the detection rate of a single optical telescope, 152 out of 412 active satellites and 135 out of 288 inactive satellites in the GSO region were selected on the basis of their visibility at the observation site in Daejeon, Korea. By using various vertical view ranges and various numbers of observations of the GSO region, the detection efficiencies were analyzed for a single night, and the numbers of follow-up observations were determined. The orbital estimation accuracies were also checked using the arc length and number of observed data points to maintain the GSO satellite catalog.
        57.
        2007.06 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to clarify the relation of the species of genus Sorbus in Korea based on multivariate analysis for the morphological characteristics and DNA polymorphism. Twenty-eight quantitative characters were assessed and analyzed by the principal component analysis and UPGMA cluster analysis. From the principal component analysis of 28 quantitative characters, three principal components (PC’s) explained the variation of inter-specific relations among the genus Sorbus. The first PC’s explained 58.95% of the variation with the Eigenvalue of 16.5, and the second and third PC’s showed the Eigenvalue of 8.3 and 3.1 and explained 88.74% and 100.0% of the variation, respectively. Especially, the first PC’s was related in order of the fruit width (FW) and length of terminal leaflet (LTL), petal length (PL), width of terminal leaflet (WTL), and diameter of winter bud (DWB). The second and third PC’s were involved in order of the No. of leaflet (NL), No. of fruit per fruiting lateral (NFL), length of upper rachis (LUR), and diameter of rachis (DR), No. of pistil (NP), respectively. Cluster analysis using them UPGMA method based on the principal components of four species of the genus Sorbus divided into two groups. Group Ⅰ comprises Sorbus commixta and S. sambucifolia var. pseudogracilis, and Group Ⅱ consists of S. amurensis and S. aucuparia. The pattern of DNA polymorphism of the 56 inter-simple sequence repeat (ISSR) markers revealed that different taxa shared different sets of bands, and DNA analysis is useful for taxonomic study on the genus Sorbus.
        58.
        2003.08 KCI 등재 서비스 종료(열람 제한)
        “Jinpumbyeo” is a new japonica rice cultivar developed from a cross between lodging tolerant semi-dwarf plant type, SR14703-60-5-GH1 and high eating quality cultivar Suweon353 by the rice breeding team of National Crop Experiment Station, RDA made in 1987
        59.
        2002.06 KCI 등재 서비스 종료(열람 제한)
        Rice plants segregating for opaque endosperm were selected and tested in every generation from F5 to F9 of a CB243/IR50 cross. Six near isogenic lines(NILs) showing difference in opaqueness, of which three lines have opaqu
        60.
        1999.09 KCI 등재 서비스 종료(열람 제한)
        Nineteen japonica and Tongil-type rices were selected from seventy nine Korean and Japanese rice cultivars grown in 1989 based on the water uptake behavior of milled rice under the room temperature and boiling conditions. The selected rice cultivars were investigated for water absorbability and some physicochemical characteristics of milled rice, proper water amount for cooking and sensory evaluation of cooked rice. The relationships among the tested grain properties were also examined. The highest varietal variation of water uptake rate was observed at twenty minutes after soaking in water. The maximum water uptake of milled rices at room temperature occurred mostly at about eighty minutes after soaking in water. Newly harvested rices showed a significantly lower water uptake rate of milled rice at 20 minutes after soaking, a relatively higher maximum water absorption ratio under the room temperature, and the less water uptake and volume expansion of boiled rice compared with the one-year old rice samples. The water uptake rate and the maximum water absorption ratio showed significantly negative correlations with the K/Mg ratio and alkali digestion value(ADV) of milled rice. The rice materials showing the higher amount of hot water absorption exhibited the larger volume expansion of cooked rice. The harder rices with lower moisture content revealed the higher rate of water uptake at twenty minutes after soaking and the higher ratio of maximum water uptake under the room temperature condition. These water uptake characteristics were not associated with the protein and amylose contents of milled rice ansd the palatability of cooked rice. The water/rice ratio(in w/w basis) for optimum cooking was averaged to 1.52 in dry milled rices (12% wet basis) with varietal range from 1.45 to 1.61 and the expansion ratio of milled rice after proper boiling was averaged to 2.63(in v/v basis). The water amount needed for optimum cooking was the lowest in Cheongcheongbyeo (Tongil-type rice) and the highest in Jinbubyeo, and the amount could be estimated with about 70% fittness by the multiple regression formula based on some water uptake characteristics, ADV and amylose content of milled rice as the independent variables. Nineteen rice cultivars were classified into seven groups based on scatter diagram projected by principal component analysis using eight properties related to water uptake and gelatinization of milled rice.
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