• 인터넷정보학회논문지
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• 제16권6호
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• pp.39-46
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• 2015

지식 공간 이론이란 학습자들이 대해 최대한의 학습 성취를 이끌어 낼 수 있도록 학습자들에 대한 가이드라인을 제공해주는 이론으로 여러 교육 환경에서 사용되어 왔다. 하지만 지식 공간 이론을 사용해왔던 많은 방법들이 주로 수작업을 통해 이루어져 왔고 이러한 작업을 지원하기 위해서 비주얼 베이직 혹은 R 등의 프로그램이 사용되어 왔지만 프로그램을 따로 배워야 하는 불편함과 시간적으로 낭비되는 등의 문제를 야기해 왔다. 본 논문에서는 이러한 문제를 해결하기 위해서 지식 공간상에서 학습자들의 지식구조를 자동으로 분석하고 결정적 학습 경로를 제공하는 이른바 지식 구조 분석 시스템을 제안한다. 제안된 시스템은 아파치 웹상에서 구현되었고, 카이 제곱 값을 산출하여 결정적 학습 흐름도를 도출하도록 하였다. 제안된 방법은 사용자들이 웹에서 편리하게 학습자들의 지식 상태 분석할 수 있도록 환경을 제공하고 지식 구조의 체계적인 검토를 위한 방법을 제시해준다.

• Structural Engineering and Mechanics
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• 제37권4호
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• pp.401-413
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• 2011

The aerodynamic stability of orthotropic tensioned membrane structures with rectangular plane is theoretically studied under the uniform ideal potential flow. The aerodynamic force acting on the membrane surface is determined by the potential flow theory in fluid mechanics and the thin airfoil theory in aerodynamics. Then, based on the large amplitude theory and the D'Alembert's principle, the interaction governing equation of wind-structure is established. Under the circumstances of single mode response, the Bubnov-Galerkin approximate method is applied to transform the complicated interaction equation into a system of second order nonlinear differential equation with constant coefficients. Through judging the stability of the system characteristic equation, the critical divergence instability wind velocity is determined. Finally, from different parametric analysis, we can conclude that it has positive significance to consider the characteristics of orthotropic and large amplitude for preventing the instability destruction of structures.

• Advances in aircraft and spacecraft science
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• 제5권6호
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• pp.615-632
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• 2018

Mechanical buckling of a rectangular functionally graded plate is obtained in the current paper using a refined higher-order shear and normal deformation theory. The impact of transverse normal strain is considered. The material properties are microscopically inhomogeneous and vary continuously based on a power law form in spatial direction. Navier's procedure is applied to examine the mechanical buckling behavior of a simply supported FG plate. The mechanical critical buckling subjected to uniaxial and biaxial compression loads are determined. The numerical investigation are compared with the numerical results in the literature. The influences of geometric parameters, power law index and different loading conditions on the critical buckling are studied.

• 대한수학회지
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• 제53권1호
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• pp.201-215
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• 2016

In this paper, we consider the following $Schr{\ddot{o}}dinger$-Kirchhoff-type equations $\[a+b\({\int}_{{\mathbb{R}}^N}({\mid}{\nabla}u{\mid}^2+V(x){\mid}u{\mid}^2)dx\)\][-{\Delta}u+V(x)u]=f(x,u)$, in ${\mathbb{R}}^N$. Under certain assumptions on V and f, some new criteria on the existence and multiplicity of nontrivial solutions are established by the Morse theory with local linking and the genus properties in critical point theory. Some results from the previously literature are significantly extended and complemented.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1998년도 춘계학술대회논문집
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• pp.21-27
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• 1998

An analysis for the prediction of wrinkling formation in curved sheets during metal froming is presented. We construct "Wrinkling Limit diagram"(WLD) which represent the combinations of the critical principal stresses for wrinkling formation in curved sheet elements subjected to biaxial plane stress. Here the scheme of plastic bifurcation theory for thin shells based on the Donnell-Mushtari-Vlasov shell theory is used. In this study, the effects of the material variables (yield stress, plastic hardening coefficient, plastic anisotropic parameter, and so on) and sheet geometry on the critical conditions for wrinkling is carried out numerically.merically.

• 산업경영시스템학회지
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• 제5권7호
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• pp.33-42
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• 1982

The standard theory of production treats human and non-human inputs in the same way. Inert Areas Theory drops this assumption. One distinction is obvious. Human capital, the source of human inputs, can not be purchased outright by firms. Usually what is purchased are units of labor time. What is critical is directed effort, at or beyond some level of skill. Direct effort, however, involves choice and motivation, and these are the critical variables left out of the standard theory. Leibenstein introduces the concept of "inert areas" by which he means "a set of effort positions whose associated levels of utility are not equal but in which the action required to go from a lower to a higher utility level involves a utility cost that is not compensated for by the gain in utility." This idea is used when discussing the behavior of firm's management.f firm's management.

• 한국지반공학회지:지반
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• 제3권4호
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• pp.7-20
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• 1987

연약지반의 다차원 압밀해석을 유한요소법으로 해석하기 위하여 점토의 구성방정식으로서 신생퇴적 점토층에서 압밀시에 예상되는 creep와 같은 변형의 시간의존성거동을 표친하는 탄 점소성 구성방정식을 새로히 제안하기 위하여 한계상태 개념으로부터 개발된 수정 cam clay 모델을 보완하여 음력변형해석을 통하여 실측치와 비교한 것이다. 그 결과 대체적으로 실측치와 접근하고 있음을 알 수 있었다.

• 영어어문교육
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• 제12권1호
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• pp.1-27
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• 2006

This study investigated how EFL readers critically read texts which are written in English. Although critical reading has been discussed in advanced EFL and ESL contexts there has not been much research on the critical reading of beginning EFL learners. Many educators are recommending that a critical perspective be adopted so that L2 learners can become empowered rather than indoctrinated. In this study, the researcher has examined the critical reading practices of five beginning level EFL readers in Korea and five first language readers of English in the United States as they read a news editorial article. The significant findings were discussed related to critical reading practice of L2 readers. The findings of the study can help the educators in English education in improving the curriculum, the teaching methodology and the learning theory for EFL reading for critical reading.

• 대한수학회지
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• 제49권6호
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• pp.1123-1138
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• 2012

We study some anisotropic boundary value problems involving variable exponent growth conditions and we establish the existence and multiplicity of weak solutions by using as main argument critical point theory.

• 수산해양기술연구
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• 제16권2호
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• pp.77-84
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• 1980

The nonstationary vibration of a rotor carrying two discs with a limited driving torque is studied theoretically by using the method of the perturbation theory. The influence of the asymmetry, torque, damping and phase difference in passing through a critical speed is studied in detail, considering the interaction between the driving source and the vibration system.