• 제목/요약/키워드: BOO

검색결과 3,901건 처리시간 0.032초

Comparative Morphology and Seasonality of Campylaephora borealis and C. crassa (Ceramiaceae, Rhodophyta)

  • Seo, Kyung-Suk;Boo, Sung-Min
    • ALGAE
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    • 제20권4호
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    • pp.325-331
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    • 2005
  • Populations of Campylaephora borealis (Nakamura) Seo, Cho et Boo and C. crassa (Okamura) Nakamura show a year-around occurrence of all life-history stages. Such a concurrency of life-history stages produces problems in recognizing species in the field. Here, we invesitgated the morphological variation and life-history stages of both species using a statistical character analysis. Life-history stage was correlated with the seawater temperature in C. borealis, whereas it was dependant on biomass in C. crassa. Thalli had dichotomous branches with adaxial branchlets. The statistics showed that the seasonal change in morphology of C. borealis was significantly different from that of C. crassa in seven qualitative characters and five quantitative characters (p < 0.001), although six quantitative features including tetrasporangial size were similar in both species. The morphological difference between the two species may be due to the annual variation of branchlet number and the variance of branch subangle.

Evolutionary status of four detached binary stars

  • Kanjanasakul, Chanisa
    • 천문학회보
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    • 제35권1호
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    • pp.49.2-49.2
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    • 2010
  • We have presented the evolutionary status of four detached double line spectroscopic eclipsing binaries which are CD Tau, CM Lac, HS Hya and ZZ Boo because the component stars of these binary systems still act as a single star. We determined the absolute dimensions of these binary systems using photometric and spectroscopic solutions from analysis of light curves and radial velocity curves. Using the luminosities, effective temperatures and masses we choose evolutionary tracks of these binary systems. Finally we obtained ages and metallicity of the stars. We found that CM Lac and HS Hya are very young stars and their ages are in range of 0.15-1.05 and 0.22-1.14 Gyrs. For CD Tau and ZZ Boo, they are older than the others and their age in range of 1.95-2.95 and 1.48-1.73 Gyrs.

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사회적 게임에서의 영아-어머니 상호작용 (Mother-Infant Interactions in Social Games)

  • 이미란;이영
    • 아동학회지
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    • 제21권3호
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    • pp.25-40
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    • 2000
  • This study investigated the development of infant behaviors and maternal scaffolding in mother-infant games. Subjects were 60 mothers and their 9-, 12-, 15- and 18-month infants, 15 dyads in each age group. Mother-infant interaction was videotaped in the laboratory as they played peek-a-boo and a ball game in 2 sessions. Infant game behaviors were classified by the Rome-Flanders, Cossette, Ricard and $D{\acute{e}}carie$(1995) list, and maternal game behaviors were classified by the Hodapp, Goldfield & Boyatzis(1984) list. Data were analyzed by one-way ANOVA, two-way ANOVA with repeated measures, sequential analysis and Z test as well as qualitative analysis. Results showed that infants played an increasingly active role with age. Infants mastered the ball game at earlier age than peek-a-boo. Mothers scaffolded infant behaviors in various ways. The amount of maternal game behavior varied by type of game.

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Contact and Near-Contact Binaries with co-relation of Mass transfer and Asymmetric Light Curve

  • Rittipruk, Pakakaew;Kang, Young-Woon
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2010년도 한국우주과학회보 제19권1호
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    • pp.32.3-32.3
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    • 2010
  • We have analyzed times of minima for six eclipsing binary systems which show asymmetric light curves. We found that five binary systems show period decrease and one system shows cyclic period variation. Three asymmetric light curves (SV Cen, RT Scl and VW Boo) are due to hot spot caused by mass transfer. Other three asymmetric light curves (AD Phe,, EZ Hya and TY Boo) are due to cool spot on the cooler component caused by magnetic activities. We also obtain absolute dimensions from photometric solution and spectroscopic solution by analyzing their light curves and radial velocity curves, collected from literatures, using 2007 version Wilson and Devinney computer code.

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Serrated Fin Tube 후류에 대한 유동가시화 적용 및 근접후류 특성에 관한 연구 (An Experimental Study of Vortex Formation of a Circular Cylinder with Serrated Fins)

  • 부정숙;김경천;류병남
    • 한국가시화정보학회:학술대회논문집
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    • 한국가시화정보학회 2002년도 추계학술대회 논문집
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    • pp.27-30
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    • 2002
  • An experimental study is performed to investigate the characteristics of near wake behind a circular cylinder with serrated fins using the constant temperature anemometer and through flow visualization. Previous report(Boo at al., 2001) shows that there are three different modes in vortex shedding behavior. This paper is focused on the identification of the physical reasons why the difference is occured in vortex shedding. The through flow velocity crossing fins decreases as increasing fin height and decreasing fin pitch mainly due to the flow resistence. Vortex shedding is affected strongly by velocity distribution around fin tube, especially by the velocity gradient. The velocity distribution at X/d=0.0 has lower gradient with increasing freestream velocity and fin height and decreasing fin pitch. Those differences in velocity gradients generate different vortex shedding mechanism.

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