• Title/Summary/Keyword: J-A$_2$ 이론

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The Meaning of Anthony Browne's Picture Book 'Gorilla' : Mainly about the Semiology of A.J. Greimas (앤서니 브라운 그림책 '고릴라' 의미연구:그레마스 기호학을 중심으로)

  • Kim, Young-Su
    • The Journal of the Korea Contents Association
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    • v.10 no.2
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    • pp.176-183
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    • 2010
  • Picture book is the artistic format to develop forms an organic relationship with text and illustration. Not only meaning which the text and illustration deliver from the picture book but understand the symbolic meaning can discover new enjoyment of reading picture book. Sees the text and illustration of the picture book at one unit which is put in indivisible relationship and analyzing in semeiology provides the viewpoint which is important in picture book comprehension. The Greimas's theory of signification leads and understands the interaction of the text and illustration of world-famous author Anthony Browne's picture book 'Gorilla'. In addition, analysing the structural connection with text and visual expression it approaches the integrated meaning of a story from a new point of view. From the researches of existing interpreted the Hanna and relationship of dad was simple being lonely but this research sees which there exists not only paternal love but also heterosexuality between Hanna and dad and could newly be interpreted with the viewpoint where heal the discord is principal.

Study of the Curing Reaction Rate of a Glass Fiber Reinforced Bisphenol-A (BPA) Epoxy Prepreg by Differential Scanning Calorimetry (DSC) (Differential Scanning Calorimetry (DSC)를 이용한 유리섬유 Bisphenol-A(BPA)계 에폭시 프리프레그의 경화 반응 속도 연구)

  • Kwon, Hyeon-Jin;Park, Hee-Jung;Lee, Eun-Ju;Ku, Sang-Min;Kim, Seon-Hong;Lee, Kee-Yoon
    • Composites Research
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    • v.31 no.1
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    • pp.30-36
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    • 2018
  • The curing behavior of glass fiber reinforced epoxy prepregs based on Bisphenol-A (BPA) was studied by differential scanning calorimetry (DSC). The total heat of reaction(${\Delta}H_{total}=280.3J/g$) was determined based on the results of the dynamic heating scanning experiments. Isothermal experiments were carried out at $110{\sim}130^{\circ}C$, and it was observed that the maximum conversion and the maximum reaction rate were increased as temperature increased. Also Kamal equation was applied to analyze autocatalytic reaction of epoxy prepregs. The higher temperatures, the greater reaction rate constants ($k_1$, $k_2$). Theoretical values were calculated by these reaction rate constants and compared with experimental values. And it was confirmed that they were in reasonable agreement. At the beginning of the reaction, the experimental data and theoretical prediction were shown the same tendency, but at the end of reaction, the experimental data were smaller than theoretical predicted values due to reaction rates controlled by diffusion.

Fracture and Hygrothermal Effects in Composite Materials (복합재의 파괴와 hygrothermal 효과에 관한 연구)

  • Kook-Chan Ahn;Nam-Kyung Kim
    • Journal of the Korean Society of Safety
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    • v.11 no.4
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    • pp.143-150
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    • 1996
  • This is an explicit-Implicit, finite element analysis for linear as well as nonlinear hygrothermal stress problems. Additional features, such as moisture diffusion equation, crack element and virtual crack extension(VCE ) method for evaluating J-integral are implemented in this program. The Linear Elastic Fracture Mechanics(LEFM) Theory is employed to estimate the crack driving force under the transient condition for and existing crack. Pores in materials are assumed to be saturated with moisture in the liquid form at the room temperature, which may vaporize as the temperature increases. The vaporization effects on the crack driving force are also studied. The Ideal gas equation is employed to estimate the thermodynamic pressure due to vaporization at each time step after solving basic nodal values. A set of field equations governing the time dependent response of porous media are derived from balance laws based on the mixture theory Darcy's law Is assumed for the fluid flow through the porous media. Perzyna's viscoplastic model incorporating the Von-Mises yield criterion are implemented. The Green-Naghdi stress rate is used for the invariant of stress tensor under superposed rigid body motion. Isotropic elements are used for the spatial discretization and an iterative scheme based on the full newton-Raphson method is used for solving the nonlinear governing equations.

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Experimental and Theoretical Investigations on the Fracture Criteria for Structural Steels (구조물용 강재의 파단기준에 대한 실험 및 이론 연구)

  • Choung, Joon-Mo;Cho, Sang-Rai
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.2
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    • pp.157-167
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    • 2008
  • Six smooth flat tensile specimens and eighteen punch specimens with three different thicknesses were machined from steel of JIS G3131 SPHC. In addition to punch tests, incremental tensile tests were conducted to obtain average true flow stress - logarithmic true strain curves. Through parametric FE simulations for the tensile specimens, material parameters related to GTN model were identified. Using indenters with three kinds of radius, punch tests were carried out to obtain fracture characteristics of punch specimens. Numerical analyses using both fracture models, GTN and $J_2$ plasticity model, gave that the former estimated well the fracture of punch specimen but the latter did not. A new concept for critical size of plate elements was introduced based on minimum relative sharpness between contact structures. Consequently, a new criterion for critical element size was proposed to be less than 20% of minimum relative radius of interacting structures.

p-Version Finite Element Model for Computation of the Stress Intensity Factors of Cracked Panels under Mixed Mode (혼합모우드를 받는 균열판의 응력확대계수 산정을 위한 p-Version 유한요소 모델)

  • 윤영필;이채규;우광성
    • Computational Structural Engineering
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    • v.9 no.2
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    • pp.133-142
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    • 1996
  • In this paper, two different techniques for mixed-mode type engineering fracture mechanics are investigated to estimate the stress intensity factors by using p-version finite element model. These two techniques are displacement extrapolation with COD and CSD method and J-integral with decomposition method. By decomposing the displacement field obtained from p-version of finite element analysis into symmetric and antisymmetric displacement fields with respect to the crack line, Mode-I and Mode-II stress intensity factors can be determined using aforementioned techniques. The example problems for validating the proposed techniques are centrally and centrally oblique cracked panels under tension. The numerical results associated with the variation of oblique angle and the ratio of crack length and panel width (a /W ratio) are compared with those by theoretical values and empirical solutions in literatures. Very good agreements with the existing solutions are shown.

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Design of a Badge Filter System for Measurement of Hp(10) with the New Type of TL Dosimeter $CaSO_4:Dy,P$ (신형 TL 선량계인 $CaSO_4:Dy,P$를 이용한 Hp(10) 측정용 배지의 필터체계 설계)

  • Kim, H.K.;Kwon, J.W.;Lee, J.K.;Kim, J.L.
    • Journal of Radiation Protection and Research
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    • v.28 no.2
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    • pp.79-85
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    • 2003
  • This study was intended to estimate Hp(10) recommended by the ICRU using the $CaSO_4:Dy,P$ element developed in the KAERI. For the estimation of Hp(10), TL response should be compensated properly through the energy range using filter materials since $CaSO_4:Dy,P$ is of severe photon energy dependent response. Various experiments and computations using Monte Carlo Code were carried out for designing filter satisfying the performance requirements of the ISO related to TL dosimeter. Under the completed filter, the relative response of $CaSO_4:Dy,P$ showed $0.75{\sim}1.0$ for photons in the range of $20{\sim}662keV$. Especially it was possible to reduce the thickness of front filter and simplify the filter combination with rear filter of larger diameter and to considerably improve angular dependence by introducing taper to the filler.

An Analysis of the Springing Phenomenon of a Ship Advancing in Waves (파랑 중에 전진하는 선박에 대한 스프링잉 현상 해석)

  • H.Y. Lee;H. Shin;H.S. Park;J.H. Park
    • Journal of the Society of Naval Architects of Korea
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    • v.38 no.3
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    • pp.41-46
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    • 2001
  • The very large vessels like VLCC and container ship have been built recently and those vessels have smaller structural strength in comparison with the other convectional skips. As a result the fatigue destruction of upper deck occurs a frequently due to the springing phenomenon at the encountering frequencies. In this study, the hydrodynamic loads are calculated by three-dimensional source distribution method with the translating and pulsating Green function. A ship is longitudinally divided into 23 sections and the added mass, damping and hydrodynamic force of each section is calculated. focusing only on the vertical motion. Stiffness matrix is calculated by the Euler beam theory. The calculation is carried out for Esso Osaka.

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A Stdy on Clutch-disc Torsional Characteristics for Torsional Vibration Reduction at Idling (공회전시 비틀림 진동 저감을 위한 클러치 비틀림 특성 연구)

  • 홍동표;정태진;김상수;태신호
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1994.04a
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    • pp.82-87
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    • 1994
  • 자동차 엔진의 주기적인 연소과정 동아네 생성된 힘에 의해 엔진의 크랭크 샤프트에 회전 불균일성이 나타난다. 이것은 엔진 플라이휘일 부분에 비틀림 변동토크를 발생시키고, 이 토크는 클러치를 통하여 변속기의 인풋기어(input gear)에 전달되어 변속기에 비틀림 진동을 일으키는 주요 원인이 된다. 공회전시 변속기에서 기어의 충돌은 주로 이 비틀림 변동토크에 의해 발생하며, 이 충돌은 차내 소음의 원인이 된다. 또한 엔진의 경량화 및 고출력화에 따른 회전수 변동의 증가는 비틀림 변동토크를 증가시켜 변속기에 커다란 진동을 초래한다. 시뮬레이션을 사용한 클러치 비틀림 기구의 적절한 특성치를 구하는 것은 클러치 설계에 효율적이고, 이미 여러 연구 결과들이 보고되었다. H.Arai은 2자유도 비선형 모델을 사용하여 클러치 접속시 발생하는 외란과 계의 안정성을 고려하여 치타음 저감을 위한 시뮬레이션을 수행하였고, S.Ohnuma은 비선형 2단 비틀림 특성을 가진 클러치 디스크의 설계에 대해서, 그리고, T.Fujimoto와 R.J.Comparin는 치타음의 발생구조와 특성을 고찰하고 비선형 비틀림 공진 저감에 의한 치타음 저감 기법에 대하여 연구하였다. 그리고, Wu Hui-Le는 자동차 동력전달계의 비틀림 진동 현상을 실험과 이론적인 계산을 통해 연구하였고, G.J.Fudala는 다자유도 모델을 이용하여 클러치의 비틀림 특성에 따라 주파수분석을 수행하여 치타음 저감 방법을 연구하였다. 또한, T.Sakai는 5자유도 모델을 이용하여 엔진 공회전시 발생하는 치타음에 대해 이론과 실험을 통해 해석하고, 엔진 회전수 변동, 클러치 특성, 변속기의 드래그(drag) 토크의 영향과 치타음 저감을 위한 개선된 클러치 특성을 제시하였다. 클러치는 동력을 전달 또는 차단하는 기능 뿐만 아니라 엔진이나 변속기에서 발생하는 소음이나 진동을 저감시키는 기능을 가지고 있다. 따라서 엔진 공회전시에 발생하는 치타음(rattle noise)이나 비틀림 진동을 저감시키는 방법으로는 여러가지가 있으나 클러치 디스크(clutch disc)의 비틀림 기구의 설계 인자들을 적절히 조절함으로써 변속기의 인풋기어에 전달되는 비틀림 진동을 저감시키는 방법이 일반적으로 수행되어지고 있다. 본 연구는 4 실린더 4 싸이클 1.5L 엔진을 장착한 경승용차의 실차실험을 통해 공회전시 엔진 플라이휘일과 인풋기어에서의 회전수 변동을 측정하고, 이 실험 데이타를 기초로 하여 엔진 토크 및 변속기에서의 드래그 토크를 계산하여 엔진-변속기 인풋기어의 반한정계 2자유도 진동모델과 비틀림 특성을 가진 클러치 디스크의 프리댐퍼 영역에 대해 시뮬레이션을 수행하여 클러치 비틀림 기구의 설계인자인 비틀림 강성, 히스테리시스 토크에 따른 비틀림 진동 저감 효과를 연구하고자 한다.

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A Study on the Continuity Expressed in Modern Fashion Design - Focusing on the Continuance Theory of H. Bergson and the Continuity theory of J. Deleuze - (현대 패션 디자인에 나타난 연속성 연구 - 베르그송의 지속 이론과 들뢰즈의 연속성 이론을 중심으로 -)

  • Yang, Hee-Young;Yang, Sook-Hi
    • Journal of the Korean Society of Costume
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    • v.58 no.2
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    • pp.15-33
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    • 2008
  • Continuity and discontinuity is a relative concept, and there are various categories of the continuity and discontinuity in our circumference. Generally, characteristics of postmodernism including between the difference and the variety have being regarded as a discontinuity. Concept of the continuity includes between the quantitative continuity and the qualitative continuity qualitative continuity has organic characteristic, which encourages creating something permanently through the flowing of the time. Therefore, this thesis has studied like this complex social condition and various relationships expressed in modern fashion focusing on permanently creative movements and behaviors equal to the 'continuance' theory of Herni Bergson and 'continuity' theory of Jill Deleuze. This thesis classifies characteristics of the qualitative continuity into spatiotemporal and spatial continuity, and subdivides into 3 sets: perceptual continuity, spatial continuity, transferring continuity of physical experience, immaterial informational continuity, and fluid continuity with environment. Continuous viewpoint, which accepts the existing elements and allows them to flow liberally, should be present more appropriative thinking direction in explaining the complex situation expressed in the modern fashion, rather than discontinuous viewpoints focused on the only changing moment.

Ferroelectric Properties and DPT in the Perovskite PMT-PT System (Perovskite PMT-PT계의 강유전 특성 및 확산상전이)

  • Kim, Y.J.
    • Journal of the Korean Vacuum Society
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    • v.17 no.2
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    • pp.122-129
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    • 2008
  • Ferroelectric properties of the PMT-PT were also studied from the temperature dependence of hysteresis loops using a method slightly modified from Sawyer-Tower's. Dielectric, pyroelectric and piezoelectric properties of the ceramics in the system PMT-PT were investigated. The resulted densities of the PMT-PT ceramics system were greater than 97 % of the theoretical value. As observed SEM micrograph of the fracture surfaces of the PMT-PT ceramics system, the average grain sizes were increased about 3-5 ${\mu}m$ to 6-8 ${\mu}m$ with increasing sintering temperature. The specimens with PT<0.30 for PMT-PT solid solution system exhibited the dielectric and pyroelectric properties of a typical relaxor ferroelectrics. The composition with the maximum dielectric constant exhibits relatively superior pyroelectric and piezoelectric properties.