검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 139

        85.
        2002.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present UBVI CCD photometry of the stellar contents and globular cluster(GC) candidates in the spiral galaxy NGC 300 in the Sculptor group. Color-magnitude diagrams for 18 OB associations having more than 30 member stars are presented. The slope of the initial mass function for the bright stars in NGC 300 is estimated to be Γ = -2.6 ± 0.3. Assuming the distance to NGC 300 of (m - M)o = 26.53 ± 0.07, the mean absolute magnitude of three brightest blue stars is obtained to be < MvBSG (3) > = -8.95 mag. We have performed search for GCs in NGC 300 and have found 17 GC candidates in this galaxy. Some characteristics of these GC candidates are discussed.
        5,500원
        86.
        2001.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        4,900원
        88.
        2001.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        6,300원
        89.
        2000.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 아시아, 유럽, 북미지역에서 두 국가간 자본시장과 금융, 자본재, 소비재, 도 ·소매서비스, 공공산업의 두 국가간 자본시장에서 국제차익거래가격결정 모형(IAPM)의 성립여부와 두 국가간 자본시장 통합여부의 결합가설을 검증하였다. 두 국가간 자본시장의 IAPM 성립여부는 요인분석과 다중회귀분석을 실시하였고, 통합여부는 Chow검증으로 분석하였다. 분석결과, 지역별, 산업별 두 국가간 자본시장이 통합되어있다는 가설을 기각할 수 없는 것으로 나와 지역별, 산업별 두 국가간 자본시장이 통합되어 있다고 밝혀졌다. 이와 같은 연구결과는 지역별, 산업별로 통합된 두 국가 자본시장에서 국제분산투자를 실시함으로써 국내분산투자 보다 더 큰 분산투자효과를 얻을 수 있다는 것을 시사한다.
        6,000원
        90.
        1998.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have made semi-analytical studies to investigate the configurations of caustics and the probability distribution of the flux factor K for the binary microlensing including external shears. A parametric equation of critical curve is derived in a 4th order complex polynomial. We present the topological dependencies of the caustics for selected gamma parameters (0, 0.3, 0.6, 1.3, 2.0, and 2.5) and convergence terms (0., 0.4, 0.8, 1.2, 1.6, and 2.0). For the purpose of analyzing the efficiency of High Amplification Event (HAE) on each caustics, we examine the probability distribution of the flux factor by a Monte Carlo method. Changing the separation of the binary system from 0.8 to 1.3 (in normalied unit), we examine the probability distribution of the K-values in various gamma parameters. The relationship between gamma parameters, seperations and their probabilties of the flux factor K have been studied. Our results show that the relatively higher K values (K>1.5) are increased as increasing the separation of the binary system. We therfore conclude that, in the N-body microlensing, the probabilities of higher HAEs are inversely proportional to the star density as well. We also point out that the present research might be used as a preliminary step toward investigating heavy N-body microlensing simulations.
        4,200원
        91.
        1996.12 KCI 등재 SCOPUS 구독 인증기관·개인회원 무료
        92.
        1996.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have analyzed vector magnetograms and Hβ filtergrams of two sunspot groups, one in a growing phase and the other in a decaying phase. In this study, the temporal evolution of their magnetic morphology has been investigated in association with solar activity. The morphological variations of the growing and decaying phase of these sunspots revealed in detail the coalescence of small spots into a large spot and the fragmentation of a large spot into many small spots, respectively. Numerous small flares were detected in the spot group during the decaying phase. This seems to be intimately associated with the shearing motions of many spots with different polarities created by fragmentation of a large sunspot. The magnetic flux and the average shear angle are found to be substantially reduced during the decaying phase, especially in the course of the flarings. This implies that the decaying phase of the sunspot is, to some degree, involved with magnetic field cancellation. The growing spot group has not shown any large activities, but numerous small spots have grown into a typical bipolar sunspot.
        4,000원
        93.
        1995.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        비압축성 물체률 위한 일반적인 유한요소 공식화는 혼히 사용되는 사각형요소에서조차 압력해의 진동화 (oscillations ) 또는 pressure ~es 현상융 나타낸다. 압력해의 안정화률 위한 규준은 소위 BabuSka-Brezzi 안정조건이며, 위의 요소들은 이 조건율 만족시키지 못한다. 본 연구에서는 선형변위해와 상수값의 압력해률 갖는 사각형요소 사용시 압력해률 안정화시키기 위해 요소의 변에서 발생하는 불연속압에 근거한 압력연속여 분치률 사용한다. 이 압력여분치률 비압축성 탄성론으로부터 유도되는 QIPO요소에 적용하며 매개변수의 변 화에 따른 수치혜의 안정화의 정도률 연구한다. 압력해는 압력 여분치 사용시 안정화될 수 있으며, 혜의 안정 화는매개변수에 민감성을나타내었다.
        4,000원
        94.
        1995.04 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present UBVRI CCD photometry of the Type Ie supernova SN 19941 in M51 which was discovered on April 2, 1994 (UT). UBVRI CCD photometry of SN 1994 I were obtained for the period of the first two months from April 4, 1994, using the Seoul National University Observatory 60 cm telescope. The light curves of SN 19941 show several interesting features: (a) SN 19941 reaches the maximum brightness at B-band on April 8.23 (B = 13.68 mag), at V-band on April 9.10 (V = 12.89 mag), and at I-band on April 10.32 (I = 12.48 mag); (b) The light curves around the maximum brightness are much narrower than those of other types of supernovae; (c) The light curves after the peak decline more steeply than those of other types of supernovae; and (d) The colors get redder from (V-R) ≈ 0.2 mag ((V - I) ≈ 0.3 mag, (B - V) ≈ 0.7 mag) on April 4 to (V-R)≈ 0.6 mag ((V-1) ≈0.9 mag, (B-V) ≈ 1.3 mag) on April 18. Afterwards (V - R) colors get bluer slightly (by ~0.005 mag/day), while (V-I) colors stay almost constant around (V-1) ≈ 1.0 mag. The color at the maximum brightness is (B-V)=0.9 mag, which is ~1 mag redder than the mean color of typical Type la supernovae at the maximum brightness. The light curves of SN 1994I are similar to those of the Type Ie supernova SN 1962L in NGC 1073. Adopting the distance modulus of (m-M)0 = 29.2 mag and the reddening of E(B - V) = 0.45 mag [Iwamoto et al. 1994, preprint for ApJ], we derive absolute magnitudes at the maximum brightness of SN 1994I, Mv(max) = -17.7 mag and MB(max) = -17.4 mag. This result shows that SN 1994I was ~2 mag fainter at the maximum brightness compared with typical Type Ia supernovae. A narrower peak and faster decline after the maximum in the light curve of SN 1994I compared with other types of supernovae indicate that the progenitor of SN 1994I might be a lower mass star compared with those of other types of supernovae.
        4,500원
        95.
        1994.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We have detected a SiO maser line (v=1, J=2- 1) for 15 stars out of about 80 long period variables in the wide range of period. No new sources are detected; all detected sources are variables with period longer than 300 days; no evidence is found that the dust grains in the outer envelope have influenced on this line. The time variation of this maser line for 7 stars, T Cep, μ Cep, U Her, R Leo, R Lmi, U Ori, and R Ser is observed and compared with optical light curve at the same epoch of maser observation. No universial relation between the time variation and the optical light curve is found. It implies that the radiation from a central star does not much play an important role for the direct pumping of the SiO maser line.
        4,600원
        96.
        1992.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        反復혜重올 받는 짧은 I 보 (Beam) 의 慣-비틀림 座때(Lateral-Torsional Buckling) 에 대한 흩윌뼈한 Parametric Study 를 逢行하여 보의 座맴現象올 좀 더 깊이 考흉하고자 한다. 有限한 비틀림햇形의 뒤틀림 (Warping) 이외에 m 少한 맺톨JTft形의 뒤틀립도 고려한 幾何學적 (完全) 非綠形의 一次7ê 보를 껴¥析的 모델 로 사용하고, 또한 金!홉의 周期的뺑性(Cyclic Plasticity) 쌓:tJJ을 보다 잘 나타내기 위해 多빼 週期的뿔性 모 덴올 Consistent Return Mapping Algorithm과 결합시켜 遭用한다. :한ì.ffI때 단방에서 아래와 갇은 여러가지 Parameter Study를 끊行함으로써 反復휴重을 받는 짧은 I 보의 함 -비블립 座며의 -압的 應홈을 ι~.흉한다 : 材料의 降ik~옳度, 降ik플래토 (Yield Plateau) , 뿔形率硬化,U-:tJJ 硬化(Kinematic Hardening) , 웰留應力, 作用倚重의 f.1端中心에 대 한 {f,í ι、率, 作用倚훌의 보 톰面에 대 한 높 이, 作用혜훨의 보 김이방향의 位置, 보 뻐f 面의 置f!{, 作用倚重으로 부터 멀리 떨어진 支持端의 固定度.
        4,600원
        97.
        1992.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lateral bracing has long been used in design practice to enhance the carrying capacity of the lateral buckling of the beam. Many factors. critically important to lateral bracing performance. do not appear in design formulas. Some of these factors are discussed in this study for the application to short 1 - beams under repeated loadings through parametric studies with an analytical model : the brace 10' cation along the length of the beam. the height of the bracing above the shear center of the beam. and the strength and stiffness of the brace. The parametric studies are carried out using a propped cantilever arrangement. and also using a geometrically (fully) nonlinear beam model for the brace as well as the beam to capture the system buckling. An idealized bracing system is configured to restrain lateral motion. but not rotation. A multiaxial cyclic plasticity model is also implemented to better represent cyclic metal plasticity in con. junction with a consistent return mapping algorithm.
        4,000원
        100.
        1983.12 구독 인증기관·개인회원 무료
        1 2 3 4 5