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        검색결과 13

        3.
        2009.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Recently, we suggested a CME earthward direction parameter as an important geoeffective parameter that has been demonstrated by front-side halo CME data. In this study, we present the geometrical implication of this parameter by comparing with the parameters from a CME cone model. Major results from this study can be summarized as follows. First, we derive an analytic relationship between the cone model parameters (the half angular width of a cone and the angle between the cone axis and the plane of sky) and the earthward direction parameter. Second, we demonstrate a close relationship between the earthward direction parameter and the cone axis angle using 32 front-side full halo CMEs. Third, we found that there is noticeable inconsistency between the cone axis angles estimated from the cone model fitting to the CMEs and from their associated flare positions, implying that the flare position should not be considered as a good earthward direction parameter. Finally we present several advantages of our earthward direction parameter in terms of the forecast of a geomagnetic storm based on CME parameters.
        4,000원
        7.
        2006.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Co-Fe-Ni-B-Si-Cr based amorphous strips containing nitrogen were manufactured via melt spinning, and then devitrified by crystallization treatment at the various annealing temperatures of for up to 30 minutes in an inert gas atmosphere. The microstructures were examined by using XRD and TEM and the magnetic properties were measured by using VSM and B-H meter. Among the alloys, the amorphous ribbons of containing 121 ppm of nitrogen showed relatively high saturation magnetization. The alloy ribbons crystallized at showed that the grain size of alloy containing 121 ppm of nitrogen was about f nm, which exhibited paramagnetic behavior. The formation of nano-grain structure was attributed to the finely dispersed Fe4N particles and the solid-solutionized nitrogen atoms in the matrix. Accordingly, it can be concluded that the nano-grain structure of 5nm in size could reduce the core loss within the normally applied magnetic field of 300A/m at 10kHz.
        4,000원
        9.
        2004.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 우리나라 고유의 유전자원인 재래산양의 체내수정란 생산기술을 확립하고자 수행하였다. 흡입법(aspiration)과 세절법(slicing)에 의해 난소 한 개당 회수된 난자의 수는 3.9개와 4.1개를 나타내어 slicing방법이 aspiration방법보다는 많은 숫자의 난자를 회수하였으나 유의적인 차이는 나타내지 않았다. 회수된 난자의 등급별 분포는 aspiration방법에서 Grade I, Grade II, Grade III, Grade IV
        4,000원
        10.
        2004.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        한국 재래산양 체내수정란 생산에 대한 발정동기화 및 과배란 유도방법과 회수된 수정란의 동결 융해 후 생존율을 조사하였다. 발정동기화를 위해 CIDR+FSH 및 CIDR+PMSG의 방법을 이용한 결과, 배란점 및 회수된 수정란의 수는 CIDR+FSH 처리구에서 16.3개 및 9.4개, CIDR+PMSG 처리구에서 16.4개 및 8.7개를 나타내어 두 처리구간에 유의적 차이는 인정되지 않았다. 회수된 수정란을 형태학적으로 평가한 결과 CIDR+FSH 처리구
        4,000원