• 대한기계학회논문집A
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• 제24권8호
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• pp.2108-2114
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• 2000

The buckling of two elastic layers bonded to a semi-infinite substrate under a transverse compressive plane strain is investigated. Incremental deformation theory, which considers the effect of the initial stress on the incremental stress field, is employed to describe the buckling behavior of both two isotropic layers and the semi-infinite substrate. The problem is converted to an eigenvalue-eigenvector case, from which the critical buckling strain and the buckling wavelength are obtained. The results are presented on the effects of the layer geometries and material properties on the buckling behavior.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2003년도 Proceeding
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• pp.10-15
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• 2003

In computer graphics, most animations of characters have been created using the traditional and often highly labor intensive key-framing technique. Recently, character animation is demanded increasingly automated techniques for animation according to interaction with the user or environment of the user. In this paper, we will propose a new method which can animate characters automatical/y with user interactions. The character's behavior is determined as a result of understanding the emotional condition of the user. Psychology and cognitive AI provide some ideas about how to approach this problem. Our study is based mostly on the theories of Ortony, Clore and Collins, which were designed to be implemented computationally. In our system, we can make 22 emotion types and some more behavior features and we apply to some characters.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
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• pp.437-450
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• 1994

The problem of testing for a change in the parameter of a stochastic process is particularly important in simulation studies. In studies of the steady state characteristics of a simulation model, it is important to identify initialization bias and to evaluate efforts to control this problem. A simulation output have the characteristics of chaotic behavior because of sensitive dependence on initial conditions. For that reason, we will apply Lyapunov exponent for diagnosis of chaotic motion to simulation output analysis. This paper proposes two methods for diagnosis of steady state in simulation output. In order to evaluate the performance and effectiveness of these methods using chaos theory, M/M/I(.inf.) queueing model is used for testing point estimator, average bias.

• 한국전산유체공학회지
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• 제19권2호
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• pp.30-39
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• 2014

We report in this paper the analysis of the motion of a needle and a spring in a viscous fluid under the influence of gravitational force. Lateral shift as well as vertical motion of a needle falling in a viscous fluid has been observed from a simple experiment. We also observed the combined rotation and translation of a falling spring. The trajectory and velocity of the falling needle and the spring were obtained by using an image processing technique. We also conducted numerical simulation for both problems. For the falling-needle problem, we employed a theory; but it turns out that significant correction is required for the solutions to match the numerical and experimental data. For the falling spring problem various theoretical formula were tested for their justification, but none of the existing theories can successfully predict the numerical and experimental results.

• 대한가정학회지
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• 제38권6호
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• pp.81-100
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• 2000

The purpose of this study was to develop the framework for the relapse prevention program. The study examined interventional needs for a relapse prevention program among adult substance abusers. The total of 107 adult substance abusers were surveyed and asked about their interventional needs for the relapse prevention program. The questionnaire was developed by the researcher on the basis of several theories such as problem behavior theory, ecologica1-developmental theory, social support theory, and coping theory. Results showed that admit substance abusers wanted the program to deal with such issues related with individual, family, social skills, and drugs. The implications of study findings were discussed.

• 한국시스템다이내믹스연구
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• 제12권4호
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• pp.63-92
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• 2011

The purpose of this paper is to investigate a possibility of applying multimethodological approach for solving a dilemma. The motivation of this attempt is that the two different approaches, the system dynamics and the theory of constraints, resemble each other in having mental models for describing the target system and using graphic tools for representing those mental models. After a brief discussion on the comparison of the two approaches, a combined method applying to the problem of dilemma is suggested. For an experimental example, the proposed approach is applied to the sales and finance conflict on an inventory issue. The study shows that the suggested approach is able to complement each other's drawbacks. Especially constructing a stock-and-flow model and implementing a computer simulation would be very useful for quantifying the system's behavior which is hardly tracked down when applying the theory of constraints alone.

• 대한수학회지
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• 제54권5호
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• pp.1573-1594
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• 2017

This paper deals with the existence and energy estimates of solutions for a class of degenerate nonlocal problems involving sub-linear nonlinearities, while the nonlinear part of the problem admits some hypotheses on the behavior at origin or perturbation property. In particular, for a precise localization of the parameter, the existence of a non-zero solution is established requiring the sublinearity of nonlinear part at origin and infinity. We also consider the existence of solutions for our problem under algebraic conditions with the classical Ambrosetti-Rabinowitz. In what follows, by combining two algebraic conditions on the nonlinear term which guarantees the existence of two solutions as well as applying the mountain pass theorem given by Pucci and Serrin, we establish the existence of the third solution for our problem. Moreover, concrete examples of applications are provided.

• 한국공간구조학회논문집
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• 제5권3호
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• pp.65-74
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• 2005

본 연구에서는 사각형 모듈의 인발성형된 복합재료 바닥판의 휨 거동에 대한 해석 모델을 개발하였다. FRP 바닥판의 해석 모델은 FSDT 평판 이론을 기반으로 임의 적층각을 지닌 FRP 바닥판의 처짐을 예측할 수 있었다. 수치적 예제에서는 네 변이 단순 지지된 등분포 하중을 받는 사각형 모듈의 FRP 바닥판을 2차원 평판 유한 요소해석을 적용하여 수행하였고, 해석 결과에 대해서는 바닥판 길이-높이의 비와 화이버 각도의 변화에 따른 효과에 대해 역점을 두고 다루었다. 연구 결과, 본 연구에서 제안한 해석 모델이 FRP 바닥판의 휨 거동을 해석하고 예측하는데 효과적이고 정확하다는 것이 입증되었다. 또한, FRP 바닥판의 높이가 높아질수록 plate 해석 이론에 있어서 일차전단변형이론(First order Shear Deformable laminated plate Theory : FSDT)이 아닌 고차전단변형(Higher order Shear Deformable plate Theory : HSDT)의 필요성에 대해 언급하였다.

• 한국IT서비스학회지
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• 제19권6호
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• pp.83-95
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• 2020

"I think security is only trying to make it uncomfortable." "10% of my work is entering IDs and passwords, such as boot passwords, mobile phone authentication numbers, etc." As reflected in the complaint above, stress caused by information security among organizations' members is increasing. In order to strengthen information security, practical solutions to reduce stress are needed because the motivation of the members is needed in order for organizations to function properly. Therefore, this study attempts to suggest key factors that can enhance security while reducing information security stress among members of organizations. To this end, based on the theory of protection motivation, trust and security stress from information security policies are set as mediating factors to explain changes in security reinforcement behavior. Furthermore, risk, efficacy, and reaction costs of cyberattacks are considered as prerequisites. Our study suggests a solution to the security reinforcement problem by analyzing the factors that influence the behavior of members of organizations. In turn, this can raise protection motivation among members.

• Structural Engineering and Mechanics
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• 제81권6호
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• pp.769-780
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• 2022

This paper studies the dynamic behavior of laminated composite circular cylindrical shells interacting with a fluid. The mathematical formulation of the dynamic problem for an elastic body is developed based on the variational principle of virtual displacements and the relations of linear elasticity theory. The behavior of an ideal compressible fluid is described by the potential theory, the equations of which together with boundary conditions are transformed to a weak form. The hydrodynamic pressure exerted by the fluid on the internal surface of the shell is calculated according to the linearized Bernoulli equation. The numerical implementation of the mathematical formulation has been done using the semi-analytical finite element method. The influence of the ply angle and lay-up configurations of laminated composites on the natural vibration frequencies and the hydroelastic stability boundary have been analyzed for shells with different geometrical dimensions and under different kinematic boundary conditions set at their edges. It has been found that the optimal value of the ply angle depends on the level of filling of the shell with a fluid. The obtained results support the view that by choosing the optimal configuration of the layered composite material it is possible to change upwards or downwards the frequency and mode shape, as well as the critical velocity for stability loss over a wide range.