• Journal of Korean Society of Steel Construction
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• v.18 no.5
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• pp.615-624
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• 2006

In the present paper, an extended composite beam theory that has no restriction on the lay-up and can account for Poisson effect which is significant for composite materials is proposed. Buckling equations for composite thin-walled members which are subjected to axial compression are derived based on the composite beam theory. In order to check the validity of the derived buckling equations, the results of experiments on the flexural-torsional buckling of vinylester/E-glass and polyester/E-glass pultruded T-section members and the flexural buckling of vinylester/E-glass pultruded H-section members are used as numerical examples. The comparison of the analytical results to the experimental and FE analysis results reveals that the proposed buckling equations predict the buckling loads of pultruded members conservatively by about 7%.

• Bulletin of the Society of Naval Architects of Korea
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• v.45 no.2
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• pp.18-23
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• 2008

• The Science & Technology
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• no.7 s.410
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• pp.90-95
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• 2003

보이는 하늘이야 같았겠지만, 문화적인 배경이 다른 민족이나 국가, 그리고 종교가 각기 다른 방식으로 우주를 이해해 왔을 것이다. 이들이 구체화되어서 설화나 신화 또는 종교의 우주관을 형성하는 과정이 달랐으리라는 것도 쉽게 상상할 수 있을것이다. 이글에서는 현대우주론이 형성 되는 과정을 서양 우주론의 관점에서 살펴보고 현대표준우주론인 대폭발 우주론에 대해서도 알아보기로 한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2003.11a
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• pp.958-963
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• 2003

In this paper a dynamic behavior of simply supported cracked pipe conveying fluid with the moving mass is presented. Based on the Timoshenko beam theory, the equation of motion can be constructed by using the Lagrange's equation. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments i.e. the crack is modelled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces across the crack section and is derived by applying fundamental fracture mechanics theory. And the crack is assumed to be in th first mode of fracture. As the depth of the crack and velocity of fluid are increased the mid-span deflection of the pipe conveying fluid with the moving mass is increased. As depth of the crack is increased, the effect that the velocity of the fluid on the mid-span deflection appears more greatly.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.134-138
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• 2003

The purpose of this study is to analyse the argument alternations in terms of semantic perspective. Argument alternation has long been an interesting topic for the linguists regardless of their linguistic schools. Semantic analysis of argument alternation is attempted by Dowty(2001) based on the Levin(1993)'s classification. The study is focused on the phenomenon where meaning changes with argument alternations even though those sentences look the same syntactically and lineally. 1 tried not only to classify verbs according to the meaning changes but to explain the alternations in semantic point of view. The verbs are divided into 4 types- Touch type, Hit type, Cut type, and Break type. Each type of verbs are tested if they show special characteristics with three alternations-Middle alternation, Body-part possessor Ascension, and Conative Alternation. And semantic analysis is tried based on that classification.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.3
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• pp.236-243
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• 2004

In this paper a dynamic behavior of a simply supported cracked pipe conveying fluid with the moving mass is presented. Based on the Timoshenko beam theory, the equation of motion can be constructed by using the Lagrange's equation. The crack section is represented by a local flexibility matrix connecting two undamaged beam segments i.e. the crack is modelled as a rotational spring. This flexibility matrix defines the relationship between the displacements and forces across the crack section and is derived by applying fundamental fracture mechanics theory. And the crack is assumed to be in th first mode of fracture. As the depth of the crack and velocity of fluid are increased the mid-span deflection of the pipe conveying fluid with the moving mass is increased. As depth of the crack is increased, the effect of the velocity of the fluid on the mid-span deflection appears more greatly.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.12
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• pp.2008-2018
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• 1997

In this study, free vibration analysis of double through-the-width split beam is studied based on the author's earlier work. Each segment which constructs double through-the-width split beam is considered as Timoshenko beam. The effect of coupling between longitudinal and transverse vibration on the natural frequencies of split beams is considered. Data acquisition and modal test of double split beam for clamped-free boundary condition are carried out. Experimental and numerical results obtained by ANSYS were compared with the calculated data by present theory and their comparisons give good agreement with one another. The influences of the size and location of double split, shear deformation, and boundary conditions on the natural frequencies are demonstrated for illustrative purpose. Effects of double split on the dynamic characteristics of beams can be used to detect the size and the location of damages in structures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.1
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• pp.116-120
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• 2007

In this study, it is presented analytic results of bending problems in the anisotropic curved thick beam and the anisotropic curved thin beam. The anisotropy is that the material properties are different in each directions and it is difficult to solve the analytical solutions because the behavior is complex. In applying numerical method to solve differential equations of anisotropic curved beams, this study uses the finite element method. Both thin beam theory and thick beam theory are used as the basic governing equations of bending problems in the anisotropic beams. The analytic results are compared between the anisotropic curved thick beams and the anisotropic curved thin beams.

• Journal of the Korean Society for Advanced Composite Structures
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• v.1 no.4
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• pp.13-17
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• 2010

A post-tensioned slab bridge is analyzed by the specially orthotropic theory. Each longitudinal and transverse steel layer is regarded as a lamina, and material constants of each lamina is calculated by the use of rule of mixture. This slab bridge with simple support is under uniformly distributed vertical and axial loads. In this paper, the finite difference method and the beam theory are used for analysis. The result of beam analysis is modified to obtain the solution of the plate analysis. The result of this paper can be used for post-tensioned slab bridge analysis by the engineers with undergraduate study in near future.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.221-221
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• 2010

NiO 산화물 타겟을 이용한 RF 마그네트론 스퍼터 방법로 glass 기판 위에 NiO 온도를 R.T(room temperature)~$400^{\circ}C$ 변화시켜 Ar 가스만을 사용하여 박막을 증착시켜, 증착 온도에 따라 NiO 박막 특성에 미치는 영향을 조사하였다. XRD 측정으로부터 증착된 박막의 결정구조는 $200^{\circ}C$이하에서 (111) 면의 우선 배향성으로 보이다가 $300^{\circ}C$ 이상에서 (220)의 우선 배향성으로 보이는 다결정 입방구조임을 확인하였다. NiO 박막의 전기적 특성의 변화는 기판의 온도가 $200^{\circ}C$까지는 $10^5\;{\Omega}cm$대를 보였고 기판의 온도가 $300^{\circ}C$ 이상에서는 $10^{-2}{\sim}10^{-1}{\Omega}cm$대로 감소하는 것을 관측하였다. 이러한 ${\sim}10^7$ 정도의 큰 저항 변화를 관측하였고, 전기적 변화 특성을 결정성, 결정립의 변화 및 NEXAFS를 통한 밴드 구조 변화 등으로 설명하였다.