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        검색결과 63

        43.
        2004.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        This is a proposal to probe local part of the interplanetary dust (IPD) cloud complex and retrieve mean volume emissivity of the local IPDs at mid-infrared wavelengths. This will be done by monitoring, with Infrared Camera (IRC) aboard the ASTRO-F, the annual modulation of the zodiacal emission. In pointing mode of the ASTRO-F mission the spacecraft can make attitude maneuvering over approximately ±1 ̊ range centered at solar elongation 90 ̊ in the ecliptic plane. The attitude maneuvering combined with high sensitivity of the IRC will provide us with a unique opportunity observationally to take derivatives of the zodiacal emission brightness with respect to the solar elongation. From the resulting differential of the brightness over the ±1̊ range, one can directly determine the mean volume emissivity of the local IPDs with a sufficient accuracy to de-modulate the annual emissivity variations due to the Earth's elliptical motion and the dis-alignment of the maximum IPD density plane with respect to the ecliptic. The non-zero eccentricity (e⊕= 0.0167) of the Earth's orbit combined with the sensitive temperature dependence of the Planck function would bring modulations of amplitude at least 3.34% to the zodiacal emission brightness at mid-infrared wavelengths, with which one may determine the IPD temperature T(r) and mean number density n(r) as functions of heliocentric distance r. This will in turn fix the power-law exponent δ in the relation T(r) = T_o(r/r_o)-δ for the dust temperature and v in n(r) = n_o(r/r_o)-v for the density. We discuss how one may de-couple the notorious degeneracy of cross-section, density, reference temperature To and exponent δ.
        4,200원
        44.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 color, texture, shape의 정보를 통합 이용하여 내용기반 영상검색 시스템의 성능을 향상시키는 기법을 고찰하였다. 먼저 영상에 내재되어 있는 color를 분석 추출하여 몇 개의 대표색으로 요약 표현한 다음, 이를 활용한 근사치 측정도를 고안하였다. Texture정보 분석에 있어서는 영상의 주축 행렬 데이터를 통계적 접근 방법으로 추출하였다. Edge분석의 방법으로는 Edge 막대그래프에서 색상변환, 양자화, 필터링에 관련된 정보를 선행처리 후 Edge 정보를 추출하였다. 마지막으로, 본 연구의 결과인 내용기반 영상검색 시스템의 효율성을 precision-recall 분석과 실험적 결과를 통하여 입증하였다.
        4,000원
        46.
        2004.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper explores an image segmentation and representation method using Vector Quantization(VQ) on color and texture for content-based image retrieval system. The basic idea is a transformation from the raw pixel data to a small set of image regions whi
        4,000원
        48.
        2004.04 구독 인증기관 무료, 개인회원 유료
        Due to the complexity and stochastic nature of automated warehousing system, items are usually queued up at I/O point. We introduce a storage/retrieval policy : dual-command. We present quick approximations to queueing phenomena under these policies. It is assumed that the storage and retrieval arrrival pattern follow the same poisson process. We also assumed that storage queue and retrieval queue being operated separately. The approximation attempts are performed under the proposed storage/retrieval policies after we derive S/R machine travel time distributions.
        4,000원
        51.
        2002.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Automated manufacturing systems are applied to shop floors as tools for increase of productivity and quality and the decrease of manufacturing lead times and industry accidents. One of the most important issue of the present day is the application of Internet. The development of Internet technologies makes manufacturing enterprises break spacial barriers between users and shop floors, and collect various field data in remote sites. In this research, an Internet-based remote control system for a small-sized automated storage and retrieval system is developed for the purpose of real-time monitoring and control of automatic production equipment. The developed system has a client-server architecture and sends real-time images of the automated storage and retrieval system to clients by an CCD camera connected to a server.
        4,300원
        55.
        1996.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to evaluate the effect of recombinant bovine somatotropin (bST; Boostin-S, LG Chem) treatment with FSH (Super OV) or PMSG on superovulatory response for transvaginal ultrasound-guided oocyte retrieval (TVR) in calves. Eight Korean Native Cattle(KNC) heifer calves; 150 to 240 days old; were randomly assigned to four treatment groups: 1) FSH(75 mg); 2) FSH (75 mg) + bST(500mg) 3) PMSG(1;000 IU); 4) PMSG(1, 000 IU) + bST(500 mg). Experimental calves in group 1 (n=2) and 2(n=2) were weekly superovulated for 4 consecutive weeks with daily injection of FSH for 3days and the next day subjected to TVR session. Animals in group 3 (n=2) and 4(n=2) were weekly stimulated for 4 consecutive weeks with a single dose of 1, 000 IU PMSG. TVR was performed on 72 hours after PMSG injection. Calves in group 2 and 4 was received injection of 500 mg of bST every 10 days. At each TVR session, follicle number and size were recorded; the oocytes collected and graded according to cumulus and cytoplasm investment. Collected oocyte were determined viable oocyte according to morphological quality with granulation of oocyte and number and status of cumlulus cells. IVM and IVF were performed and assessed cleavage rate on day 3 after fertilization. A Sonovet 600(Medison, Co., Ltd) realtime ultrasound scanner with a 6.5 MHz convex transducer, fixed at the tip of 500 mm estended handle equipped with a needle guide was used in collecting oocyte. Differences between groups were analysed by chi-square test. The population of large follicle (5 nun) and aspiration rate were not significant different among the 4 groups. But, the number of small follicles (<5 mm) and aspirated oocyte in the KNC calves treated with bST were 1.3~1.6 times higher than in KNC calves treat with FSH or PMSG alone. In conclusion, the administration of bST with FSH or PMSG at superovulation for TVR in calves was increase the nurnber of small follicle which was influenced the number of aspiratable follicle.
        4,000원
        56.
        2018.07 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 반복학습과 반복인출연습이 학습 파지에 미치는 효과를 비교해 보기 위하여 중학교 3학년 52명을 피험자로 하여 산문자료 학습 후 단답형과 선택형 문제형식으로 2018년 3월 20일 1차 검사, 1주 지연 후에 2차로 장기 파지를 검사하였다. 그 결과, 단답형에서는 반복인출연습이 반복학습에 비해 더 높은 수행을 보였고, 선택형에서는 반복학습과 반복인출연습의 효과가 비슷하게 나타났다. 그리고 학습조건과 문제유형은 단기 파지에서만 유의미하게 상호작용효과가 있는 것으로 나타났다. 이를 통해 상대적으로 인출을 위한 많은 노력이 요구되는 재생(recall)에서는 단순히 학습 내용을 반복학습하는 것보다는 반복인출해 보는 것이 더욱 효과적인 것으로 판단된다. 이것은 Bjork의 ‘바람직한 어려움(desirable difficulty)’과도 일치하며, 학습 파지에서 인출연습의 효과를 강력히 지지하는 것으로 볼 수 있다. 그러므로 실제 교실 수업에서도 형성평가나 퀴즈 등의 형태로 인출연습을 해 보는 것이 학습 파지에 효과적이라는 것을 제안한다.
        57.
        2016.05 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 GCOM-W1 위성에 탑재된 Advanced Microwave Scanning Radiometer 2 (AMSR2) 센서의 토양수분 자료를 Land Parameter Retrieval Model (LPRM) 알고리즘을 통해 전처리하여 2014년도 한반도 지점관측 자료와의 비교 분석을 수행, 위성 토양수분 자료 의 적합성을 평가하였다. 통계 분석 결과 AMSR2 X-band의 토양수분 자료는 38개의 지점관측 자료와 비교해 0.03의 평균 bias, 0.16의 평균 RMSE의 낮은 오차 수준을 보였으며, 최대상관계수는 0.67로 나타났다. 또한 AMSR2 센서의 ascending, descending 시간대별 위성 토양수분 자료 분석과 X, C1, C2-band의 주파수 영역별 위성 토양수분 자료 분석 결과, ascending overpass time 시간대와, X-band 주파수의 토양수분 자료가 지점 관측 자료와 더 좋은 상관관계를 보였다. 본 연구의 분석 결과는 한반도에서 최근 문제가 되고 있는 가뭄을 비롯한 각종 재해 분석 시 토양수분의 공간적 분포를 연구하는데 활용 될 수 있을 것으로 기대된다.
        58.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        Climate change is the most direct threatening factors in sustaining agricultural productivity. It is necessary to reduce the damages from the natural hazards such as flood, drought, typhoons, and snowstorms caused by climate change. Through the vulnerability assessment to adapt the climate change, it is possible to analyze the priority, feasibility, effect of the reduction policy. For the vulnerability assessment, broad amount of weather data for each meterological station are required. Making the database management system for the meteorologic data could troubleshoot of the difficulties lie in handling and processing the weather data. In this study, we generated the meteorologic data retrieval system (MetSystem) for climate change vulnerability assessment. The user interface of MetSystem was implemented in the web-browser so as to access to a database server at any time and place, and it provides different query executions according to the criteria of meteorologic stations, temporal range, meteorologic items, statistics, and range of values, as well as the function of exporting to Excel format (*.xls). The developed system is expected that it will make it easier to try different analyses of vulnerability to natural hazards by the simple access to meteorologic database and the extensive search functions.
        59.
        2009.03 KCI 등재 서비스 종료(열람 제한)
        This study presents the analysis of an atmospheric flow around a single-doppler radar located in a pseudo-site. The use of a doppler radar in meteorological field of wind engineering has become widespread over the last several decades, but it has generally been recognized that the single-Doppler radar yields only one single velocity component - the radial velocity(Vr) so that some additional hypotheses or simplifications must be necessary to get proper wind forecast. Therefore, in order to get an accurate radial velocity(Vr) in this study, the existing methods such as VAD(Velocity Azimuth Display) and VARD(Velocity Area Display) are reformulated and applied to match the previous study(Waldteufel and Corbin1)), which have been an important indicator for retrieving a radar velocity. The results presented in this study include the results from different assessment methods in a peudo-site of different wind fields. Unless the existing method can consider the proper decomposition of radial velocity in the real site, then authors suggest an appropriate curve-fitting to decrease the uncertainty errors by changing a grid adaptation rate or applying a weighting function with respect to the wind angle. It is concluded that provided properly formulated fitting function are used, the wind retrieval from the Doppler radar using VAD and VARD methods can be a viable tool for use in wind engineering problems searching for the wind resources.
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