• Title/Summary/Keyword: Yamada

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Elachista tenuis Yamada (Phaeophyta) from Kangneung, Eastern Coast of Korea (갈조류의 일미기록종 Elachista tenuis Yamada(알쏭이 모자반털: 신칭))

  • 유순애
    • Journal of Plant Biology
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    • v.19 no.3
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    • pp.92-94
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    • 1976
  • Elachista tenuis Yamada, epiphytic on Sargassum confusum, is reported for the first time in Korea. It forms hemispherical tufts by pseudoparenchymatous medulla and assimilatory filaments. The cells ofassimilatory filament are not constricted at septa, and nearly equal in breadth from base to apex. Plurilocular sporangia are rather abundant, while unilocular sporangia rare.

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A Comparative Study of k-ε Algebraic Stress Model and Mellor-Yamada Model Applied to Atmospheric Dispersion Simulation Using Lagrangian Particle Dispersion Model (라그랑지 입자 모델을 이용한 k-ε Algebraic Stress Model과 Mellor-Yamada Model의 비교 연구)

  • 김상백;오성남
    • Journal of Korean Society for Atmospheric Environment
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    • v.20 no.1
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    • pp.47-58
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    • 2004
  • The $textsc{k}$-$\varepsilon$ algebraic stress model (KEASM) was applied to atmospheric dispersion simulation using the Lagrangian particle dispersion model and was compared with the most popular turbulence closure model in the field of atmospheric simulation, the Mellor-Yamada (MY) model. KEASM has been rarely applied to atmospheric simulation, but it includes the pressure redistribution effect of buoyancy due to heat and momentum fluxes. On the other hand, such effect is excluded from MY model. In the simulation study, the difference in the two turbulence models was reflected to both the turbulent velocity and the Lagrangian time scale. There was little difference in the vertical diffusion coefficient $\sigma$$_{z}$. However, the horizontal diffusion coefficient or calculated by KEASM was larger than that by MY model, coincided with the Pasquill-Gifford (PG) chart. The applicability of KEASM to atmospheric simulations was demonstrated by the simulations.s.

A study on the parameter estimation of S-Shaped Software Reliability Growth Models Using SAS JMP (SAS JMP를 이용한 S형 소프트웨어 신뢰도 성장모델에서의 모수 추정에 관한 연구)

  • 문숙경
    • Journal of Korean Society for Quality Management
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    • v.26 no.3
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    • pp.130-140
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    • 1998
  • Studies present a guide to parameter estimation of software reliability models using SAS JMP. In this paper, we consider only software reliability growth model(SRGM), where mean value function has a S-shaped growth curve, such as Yamada et al. model, and ohba inflection model. Besides these stochastic SRGM, deterministic SRGM's, by fitting Logistic and Gompertz growth curve, have been widely used to estimate the error content of software systems. Introductions or guide lines of JMP are concerned. Estimation of parameters of Yamada et al. model and Logistic model is accomplished by using JMP. The differences between Yamada et al. model and Logistic model is accomplished by using JMP. The differences between Yamada et al. model and Logistic model is discussed, along with the variability in the estimates or error sum of squares. This paper have shown that JMP can be an effective tool I these research.

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New Records of Four Hydroids (Cnidaria, Hydrozoa) in Korea (한국미기록 히드라충류 (자포동물문: 히드라충강) 4종)

  • 박정희
    • Animal Systematics, Evolution and Diversity
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    • v.15 no.2
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    • pp.197-204
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    • 1999
  • Some marine hydroids were collected from the eastern sea of Korea during the period from June 1989 to July 1997. Among the identified species four hydroids: Bimeria annulata (Nutting, 1901), Bougainvilla ramosa (van Beneden, 1844), Eudendrium boreale Yamada, 1954 and Plumularia undulata Yamada, 1950 were turned out to be new to Korean fauna.

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Strength of UD-Fabric Hybrid Laminated Composite Joints Based on Progressive Failure Analysis (점진적 파손해석 기법을 이용한 일방향-평직 혼합 적층 복합재 체결부의 강도)

  • 신소영;안현수;권진회
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.05a
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    • pp.17-21
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    • 2002
  • A finite element method based on the two-dimensional progressive failure analysis is presented for characterizing the strength and failure of the unidirectional-fabric hybrid laminated composite joints under pin loading. The 8-node laminated shell element is incorporated in the updated Lagrangian formulation. Various failure criteria including the maximum stress, Tsai-Wu, Yamada-Sun, and combinations of them are used in conjunction with the complete unloading stiffness degradation method. For the verification, joint tests are conducted for the specimens with various geometries. Although there are some differences depending on the geometry, the finite element model using the Yamada-Sun or the combined Yamada-Sun and Tsai-Wu criterion predicts the failure strength best.

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Anti-inflammatory Effects on 80% Ethanol Extract and Ethyl Acetate Fraction of Acrosorium yendoi Yamada in Murine Macrophage RAW 264.7 Cells (Murine Macrophage RAW 264.7 세포에서 누은분홍잎(Acrosorium yendoi Yamada)의 추출물과 에틸아세테이트 분획물에 대한 항염증 효과)

  • Ko, Chang-Sik;Hyun, Woo-Cheol;Kim, Ji-hyun;Ko, Yeong-Jong;Song, Sang Mok;Ko, Mi-Hee;Lee, Jong-Chul;Kim, Chang-Sook;Yoon, Weon-Jong
    • Korean Journal of Plant Resources
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    • v.28 no.5
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    • pp.574-581
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    • 2015
  • This study describes a preliminary evaluation of the anti-inflammatory activity of Acrosorium yendoi Yamada extracts. A. yendoi Yamada was extracted using 80% ethanol and then fractionated sequentially with n-hexane, ethyl acetate and butanol. To screen for anti-inflammatory agents effectively, we first examined the inhibitory effect of 80% EtOH extract and solvent fractions of A. yendoi Yamada on the production of pro-inflammatory factors and cytokines stimulated with lipopolysaccharide. In addition, we examined the inhibitory effect of 80% EtOH extract and solvent fractions of A. yendoi Yamada on pro-inflammatory mediators (NO, iNOS, PGE2, and COX-2) in RAW 264.7 cells. In the sequential fractions of n-hexane and EtOAc inhibited the NO and PGE2 production and the protein level of iNOS and COX-2, and protein expression of pro-inflammatory cytokines (TNF-α, and IL-6). These results suggest that A. yendoi Yamada may have significant effects on inflammatory factors and may be provided as possible anti-inflammatory therapeutic seaweed.

Failure Strength of the Composite Mechanical Joint according to the Stacking Angle (적층각 변화에 따른 복합재료 기계적 체결부의 파손강도)

  • Jo, Dae-Hyeon;Kim, Cheol-Hwan;Choi, Jin-Ho
    • Composites Research
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    • v.30 no.4
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    • pp.229-234
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    • 2017
  • Generally, joints are the weakest part in the composite structures. Composite joints can be classified into adhesive joints and mechanical joints, and mechanical joints are mainly used in areas less sensitive to environmental conditions. In this paper, the failure loads of composite mechanical joints with five different stacking angles are tested and predicted. Finite element analysis of mechanical joints were performed and failure loads were predicted by the FAI(Failure Area Index) method using Tsai-Wu and Yamada-Sun failure criteria, and the predicted failure loads were compared with experimental results. From the experiment and analysis, the failure loads of the mechanical joints were decreased as the ratio of 0 degree layer was low and they could be predicted within 13.03% using the FAI method and Yamada-Sun failure criteria.