• Journal of Advanced Marine Engineering and Technology
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• 제23권3호
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• pp.338-345
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• 1999

The objective of this study is to developed the refrigeration vehicle system installed eutectic olu-tion plates which consists of copper tubes carrying the refrigerant between two aluminum plates and the space between the plates filled with eutectic solution. The numerical analysis for the loca-tion of plates to get the uniform low temperature distribution in storage space was carried out and the result showed that the top left-side and right-side walls were the proper places to install plates. For three different concentrations of ethylene glycol solution the temperature distribution of inside space were measured during the day time of summer and the 21% solution was found to be properto sustain the temperature of $5-10^{\circ}C$ for milk transportation. The result showed that the refrigeration truck installed eutectic plates was very efficient to keep the milk fresh during vehicle transportation.

• Structural Engineering and Mechanics
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• 제23권2호
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• pp.115-127
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• 2006

The axisymmetric free vibrations of transversely isotropic magnetoelectroelastic laminated circular plates are studied. Based on the three-dimensional governing equations of magnetoelectroelastic medium, the state space equations of laminated circular plates are obtained. By using the finite Hankel transform and rendering the free terms left by the transform in terms of the boundary quantities, the solutions of the state space equations are given for two kinds of boundary conditions. The frequency equations of the free vibration are derived using the propagator matrix method and the boundary conditions at top and bottom surfaces. By virtue of the inverse Hankel transform, the mode shapes are also determined. Since the solutions strictly satisfy the governing equations in the region and the boundary conditions at the edges, they are the three-dimensionally exact. Finally, the natural frequencies of such plates are tabulated and compared with those of the piezoelectric and elastic plates in the numerical example.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2001년도 추계학술대회 논문집
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• pp.283-285
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• 2001

The most work-space invest much time and labor for optimal arrangement. The work-plates of the work-space should be arranged, processed and assembled under the restricted work space. The optimal arrangement under the terms of a restriction arrange the maximum work-plates in appointed work-space. It's the central aim. The work-plates arrangement scheduling of the most work-space are achieved through the experience of the planner. Like this, if the work-plates arrangement is worked by hand, there spend much time for the training planner. And the burden of the personnel expenses occur for using the master worker, also there are dangerous factors to be able to bring the bottleneck circumstance for the process planning, because the quick work planning does not accomplish. With such problems, the biggest problem is inferior the value of the plan. For solved the such problem of hand-operating, some work-spaces developed and used the work-plate arrangement scheduling system for the special quality of themselves. This paper make research into a plan to develop the work-plate arrangement scheduling system efficiently.

• 한국안전학회지
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• 제33권5호
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• pp.42-50
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• 2018

The Chemical Controls Act strictly regulates for the chemical companies to establish sufficient space between the liquid chemical tank and dike, but facilities already installed suffer from the space shortage between the tank and dike. Installing leakage preventing plates on the dike is considered as one of the economic solutions that can alleviate the space deficiency. However, there is no technical and reasonable criterion for the safety evaluation of the leakage preventing plate on the dike. In order to address this problem, we provide generalized and verified calculating equations that give maximum height and horizontal distance of leakage trajectories. Through the proposed equations, proper heights of the leakage preventing plates on the dike can be easily determined. In this study, new calculating methods are also developed to determine the impact force of the liquid to the leakage preventing plates. In addition, we performed the reactivity experiments between four corrosive liquid chemicals and two stainless steel materials that are candidate substances for the construction of the leakage preventing plate. The results of this study is expected to be applicable as a guideline in the design of safe dike and its leakage preventing plates.

• Steel and Composite Structures
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• 제22권1호
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• pp.161-182
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• 2016

A state space differential reproducing kernel (DRK) method is developed for the three-dimensional (3D) analysis of functionally graded material (FGM) axisymmetric circular plates with simply-supported and clamped edges. The strong formulation of this 3D elasticity axisymmetric problem is derived on the basis of the Reissner mixed variational theorem (RMVT), which consists of the Euler-Lagrange equations of this problem and its associated boundary conditions. The primary field variables are naturally independent of the circumferential coordinate, then interpolated in the radial coordinate using the early proposed DRK interpolation functions, and finally the state space equations of this problem are obtained, which represent a system of ordinary differential equations in the thickness coordinate. The state space DRK solutions can then be obtained by means of the transfer matrix method. The accuracy and convergence of this method are examined by comparing their solutions with the accurate ones available in the literature.

• 한국항공우주학회지
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• 제38권10호
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• pp.1031-1037
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• 2010

이 논문에서는 소형 정찰 UAV의 동력원으로 연료전지 시스템을 적용하기 위해, 기존의 흑연 분리판을 대체할 수 있는 가벼운 알루미늄 분리판을 제시하였다. 분리판은 연료전지 시스템 전체 무게의 80% 이상을 점유하므로, 경량의 알루미늄 분리판은 연료전지 UAV의 유효 탑재량과 항속 시간을 증가시킬 수 있다. 일반적으로 사용되고 있는 흑연 재질의 분리판과 성능을 비교 및 평가하기 위해 알루미늄과 흑연 분리판을 제작하였으며, 알루미늄 분리판의 성능이 흑연 분리판에 비해 약 15% 이상 증가하였음을 확인하였다. 또한, 실제 소형 정찰 UAV에 적용하기 위한 기초 연구로써 알루미늄 분리판을 이용한 단전지의 성능을 다양한 운전조건에서 측정하였다.

• Structural Engineering and Mechanics
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• 제88권6호
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• pp.589-598
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• 2023

This article addresses the quasi-static analysis of time-dependent honeycomb sandwich plates with various geometrical properties based on the bending analysis of elastic honeycomb sandwich plates employing a time function with three unknown coefficients. The novel point of the developed method is that the responses of viscoelastic honeycomb sandwich plates under static transversal loads are clearly formulated in the space and time domains with very low computational costs. The mechanical properties of the sandwich plates are supposed to be elastic for the faces and viscoelastic honeycomb cells for the core. The Boltzmann superposition integral with the constant bulk modulus is used for modeling the viscoelastic material. The shear effect is expressed using the first-order shear deformation theory. The displacement field is predicted by the product of a determinate geometrical function and an indeterminate time function. The simple HP cloud mesh-free method is utilized for discretizing the equations in the space domain. Two coefficients of the time function are extracted by answering the equilibrium equation at two asymptotic times. And the last coefficient is easily determined by solving the first-order linear equation. Numerical results are presented to consider the effects of geometrical properties on the displacement history of viscoelastic honeycomb sandwich plates.

• 정보처리학회논문지D
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• 제13D권1호
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• pp.125-132
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• 2006

현재의 차량번호인식 시스템은 외부의 잡음환경 때문에 안정적인 추출이 쉽지 않은 실정이다. 본 논문에서는 YUV컬러 공간변환을 이용하여 잡음환경에서도 인식률과 안정성이 높은 차량번호판 영역추출 방법을 제안한다. 차량번호판 컬러에서 RGB컬러 모델이 처리 시간은 빠르나 잡음환경에서는 인식률이 저조하고 밝기 정보가 별도로 표시되는 인자가 없으므로, RGB형식보다 빛에 둔감하고 데이터 량이 적은 YUV컬러 공간의 U채널과 V채널을 단계별 또는 재조합하는 방법으로 차량번호판 영역을 추출하였다. 차량번호판 영역은 라벨링된 영상의 기하학적 특성인 크기와 위치로 추출하였다. 본 논문에서 제안한 알고리즘은 여러 가지 잡음환경에서도 육안으로 구분할 수 있는 차량번호판을 모두 추출할 수 있음을 검증하였다.

• Composites Research
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• 제30권5호
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• pp.273-279
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• 2017

This paper describes the fabrication techniques and analysis of hybrid composite plates with an active frequency selective surface (FSS). For fabricating hybrid composite plate with active FSS, an active FSS with a resonance frequency located in the C band can obtained using varactor diodes. The hybrid composite plate was first designed and simulated to determine its electromagnetic properties using the commercial software HFSS. After simulation, active FSSs and hybrid composite plates were fabricated by mounting with varactor diodes. After fabrication, free space measurement was used to determine the electromagnetic properties of active FSS and the hybrid composite plates. The simulation and experimental results were in good agreement.

• International Journal of Aeronautical and Space Sciences
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• 제12권2호
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• pp.200-209
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• 2011

An analytical solution for rectangular laminated composite plates was obtained via a formal asymptotic method. From threedimensional static equilibrium equations, the microscopic one-dimensional and macroscopic two-dimensional equations were systematically derived by scaling of the thickness coordinate with respect to the characteristic length of the plate. The onedimensional through-the-thickness analysis was performed by applying a standard finite element method. The derived twodimensional plate equations, which take the form of recursive equations, were solved under sinusoidal loading with simplysupported boundary conditions. To demonstrate the validity and accuracy of the present method, various types of composite plates were studied, such as cross-ply, anti-symmetric angle-ply and sandwich plates. The results obtained were compared to those of the classical laminated plate theory, the first-order shear deformation theory and the three-dimensional elasticity. In the present analysis, the characteristic length of each composite was dependent upon the layup configurations, which affected the convergence rate of the method. The results shown herein are promising that it can serve as an efficient tool for the analysis and design of laminated composite plates.