• Proceedings of the KSME Conference
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• 2000.11a
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• pp.475-480
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• 2000

The transient dynamic-response analysis of fuel-storage tanks of flying vehicles accelerating in the vertical direction is achieved with finite element method. A fuel-storage tank is a representative example of the fluid-structure interaction problem, in which structure and fluid media interact strongly. For the accurate analysis of this complicated fluid-structure system, we employed ALE(arbitrary Lagrangian-Eulerian) coupling method. Two types of fuel-storage tanks, one with two baffles and the other without baffle, are considered to examine the effect of baffles. The fuel-storage tank with baffles shows more uniform hydrodynamic pressure distribution, resulting effective stress in structural region and faster convergence from transient to steady states. MSC/Dytran, a commercial FEM software for the 3D coupled dynamic analysis, is used for this analysis.

• Journal of the military operations research society of Korea
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• v.24 no.2
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• pp.117-129
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• 1998

This study is concerned with developing a heuristic for a web-based vehicle routing problem using mixed genetic algorithm(VRPMGA) which determines each vehicle route in order to minimize the transportation costs, subject to meeting the demands of all delivery points. VRP is known to be NP-hard, and it needs a lot of computing time to get the optimal solution, so that heuristics are more frequently developed than optimal algorithms. This study aims to develop a mixed genetic algorithm by partitioned strategy which can give a good solution in comparatively brief time. The good features of the VRPMGA are, fristly, the ability of early convergence and, secondly, the capability of producing multiple, alternative, and near-optimal solutions. The VRPMGA is a useful algorithm that can be appliable to VRP and TSP. Finally, the computational test were performed using the benchmark problems and the proposed heuristic is compared with the other existing algorithms (COSA). The result of computational tests shows that proposed heuristic gives good solutions, in much shorter time, which are same as the best known solutions in the pervious research.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.19 no.4
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• pp.387-407
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• 2015

This paper analyzes the $h{\times}p$ version of the finite element method for optimal control problems constrained by elliptic partial differential equations with random inputs. The main result is that the $h{\times}p$ error bound for the control problems subject to stochastic partial differential equations leads to an exponential rate of convergence with respect to p as for the corresponding direct problems. Numerical examples are used to confirm the theoretical results.

• Structural Engineering and Mechanics
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• v.10 no.5
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• pp.451-462
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• 2000

Buckling loads are determined for thin isotropic circular cylindrical shell panels subject to radial pressure using the new differential quadrature method. The Budiansky stability theory serves as the basis of the analysis. For this problem involving four boundary lines a two-dimensional approach is used, and a detailed convergence study is carried out to determine the appropriate analysis parameters for the method. Numerical results are determined for a total of twelve cylindrical shell panel cases for a number of different boundary support conditions. The results are compared with analytical and finite element method results. Conclusions are drawn about the technical significance of the results and the solution process.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1999.10a
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• pp.395-402
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• 1999

This paper discusses the theoretical researches subject to elastic buckling problems of the structures. The purpose is to ensure the characteristic of buckling be true by arc-length method and the finite element method. The difficulties in processes calculating the equilibrium curve after buckling is to get the equilibrium owe near singular point at which the determinant of stiffness matrix is zero. The purpose of the load-displacement curve is to determine the buckling load of the structure, and further to get the information about the characteristic after buckling. Here, this paper expresses the incremental solution at particular point by the linear combination of both homogeneous mode and particular mode, then uses the method which gets the unknown parameter including this function, through trial-and-error method including modified N-R convergence process. Finally, this paper describes the multiple bifurcation of truss dome as the numerical examples according to this algorithm.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.07a
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• pp.87-88
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• 2014

접근통제는 주체가 객체와 상호작용하는 방법의 관리에 대한 것이다. 객체에서 주체로의 정보전송을 접근 이라고 한다. 주체는 접근을 통하여 수동적 실재 즉, 객체에 대한 정보 또는 객체로부터 데이터를 요구하는 능동적 실재이다. 주체는 항상 객체에 대한 정보 또는 객체로부터 데이터를 수신하는 실재이며, 또한 객체에 대한 정보 또는 객체로부터 데이터를 수신하는 실재이며 또한 객체에 대한 정보 또는 객체 내에 보관되어 있는 데이터를 변경하는 실재이다. 객체는 항상 정보 혹은 데이터를 제공하거나 유지하는 실재이다. 업무수행자(사용자)의 역할(Role)과 데이터 사용행위에 기반한 접근 및 권한 통제가 이루어져야 한다. 중요 정보의 대량 조회 및 변경 작업은 사전 결재를 득해야 한다. 일정 시간 무행위 세션에 대해 통제를 해야 한다.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.1
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• pp.57-61
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• 2015

The level of change in distant PTC, near PTC, distant NTC, and near NTC was measured divided by before and after viewing 3D images. The 50 examinees were categorized into Low/ Middle/ High groups according to the level of change by test subject. Among all the entries, the exophoria group showed the highest change distribution, and in the distant and near NTC entries showed statistically significant differences in variation.

• Bulletin of the Society of Naval Architects of Korea
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• v.18 no.3
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• pp.1-9
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• 1981

In this paper, it is demonstrated that, with the distribution of lowest order concentrated(discrete) singularities of delta function nature, the solution to the linear free surface problem can be obtained with a remarkable degree of accuracy. The linear boundary value problem is formulated subject to boundary conditions for the determination of strengths of singularities; the simple sources above(not on) the free surface and the vortices on the body surface. Three sample calculation were performed` the flow about a submerged vortex of known strength, the flow past a submerged circular cylinder, and the flow around a hydrofoil section. The convergence of the numerical procedure is achieved with a relatively small number of elements. The final results are compared with those of the published works, and are considered very satisfactory.

• Journal of information and communication convergence engineering
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• v.2 no.1
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• pp.32-35
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• 2004

Human ability to perceive colors is a very subjective matter. The task of measuring and analyzing appropriate colors from colored images, which matches human sensitivity for perceiving colors, has been a challenge to the research community. In this paper we propose a novel approach, which involves the use of fuzzy logic and reasoning to analyze the RGB color intensities extracted from sensory inputs to understand human sensitivity for various colors. Based on this approach, an intelligent system has been built to predict the subject's personality. The results of experiments conducted with this system are discussed in the paper.

• Journal of Korean Clinical Health Science
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• v.9 no.2
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• pp.1520-1525
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• 2021

Purpose. This study conducted visual function training for children under 12 years of age who relapsed after surgery for intermittent exotropia. We are trying to find out whether the visual function has been improved by visual function training. Methods. After surgery, the subject with recurrent exotropia was given a prescription for refractive error, followed by visual function training and vision therapy with visual sence using prisms and lenses. Results. The subjects' positive relative convergence improved to 19.69𝚫, corrected visual acuity improved to 0.88, and stereoscopic vision function improved to 53.08 arc second. It was found that the smaller the angle of deviation at the time of recurrence after surgery, the better the vision therapy effect. Conclusions. It can be seen that visual function training is helpful in improving visual function, and the importance of visual function training can be known.