• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.777-780
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• 2005

The high vacuum in a electron beam lithography is basic condition, because electron beam vanish by collision with air molecules in generally atmosphere. To make high vacuum state, the vacuum control valve is essential. Most vacuum control valve are manual units. So, user of manual vacuum valve must have understanding vacuum process to change from low vacuum to high vacuum state. The user of electron beam lithography are troubled with operation of manual vacuum valve, in case the vacuum chamber is frequently open. In this paper, the design and performance test of auto vacuum control valve for electron beam lithography are described. With the auto vacuum control valve, the high vacuum level can reach 2.8E-5 Torr.

• Proceedings of the KWS Conference
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• 2003.11a
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• pp.24-26
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• 2003

In this study EB(Electron Beam) welder was modified to apply EB welder to micro-joining with solder ball and Pt wire. The power and beam current of EB welder is 6kW, 100mA and the minimum current was 1mA. The minimum current of EB welder was modified to decrease the amount of beam current to 0.0lmA and the monitoring system to observe materials was made up. The control system and CAD/CAM software for e-beam direct writing was developed and the deflection beam was controlled without moving workpieces. the possibility of applying EB welder to micro-joining with solder ball and Pt wire was studied through this experiments.

• Smart Structures and Systems
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• v.13 no.4
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• pp.517-546
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• 2014

This paper proposes a refined electro-mechanical beam formulation. Lagrange-type polynomials are used to interpolate the unknowns over the beam cross section. Three- (L3), four- (L4), and nine-point(L9) polynomials are considered which lead to linear, bi-linear, and quadratic displacement field approximations over the beam cross-section. Finite elements are obtained by employing the principle of virtual displacements in conjunction with the Carrera Unified Formulation (CUF). The finite element matrices and vectors are expressed in terms of fundamental nuclei whose forms do not depend on the assumptions made. Additional refined beam models are implemented by introducing further discretizations, over the beam cross-section. Some assessments from bibliography have been solved in order to validate the electro-mechanical formulation. The investigations conducted show that the present formulation is able to detect the electro-mechanical interaction.

• Proceedings of the Korean Vacuum Society Conference
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• 2003.02a
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• pp.229-229
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• 2003

• Proceedings of the Korean Vacuum Society Conference
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• 2003.08a
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• pp.216-216
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• 2003

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.109-110
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• 2000

Sputtering yield of MgO film in the AC-PDPs has been calculated by Monte Carlo simulation of ion scattering. In the ion energy range less than 50 eV, the sputtering yield is 4 ${\times}$ $10^{-4}$ for Xe ions and it is between 0.1 and 0.01 for He, Ne, and Ar ions. The erosion rate is estimated about $25{\AA}$ per hour for Xe ions in an actual PDP plasma for sustain and full white mode.

• Coupled systems mechanics
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• v.4 no.1
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• pp.99-114
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• 2015

In this paper, a refined exponential shear deformation beam theory is developed for bending analysis of functionally graded beams. The theory account for parabolic variation of transverse shear strain through the depth of the beam and satisfies the zero traction boundary conditions on the surfaces of the beam without using shear correction factors. Contrary to the others refined theories elaborated, where the stretching effect is neglected, in the current investigation this so-called "stretching effect" is taken into consideration. The material properties of the functionally graded beam are assumed to vary according to power law distribution of the volume fraction of the constituents. Based on the present shear deformation beam theory, the equations of motion are derived from Hamilton's principle. Analytical solutions for static are obtained. Numerical examples are presented to verify the accuracy of the present theory.

• Transactions on Electrical and Electronic Materials
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• v.9 no.3
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• pp.120-122
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• 2008

We have studied the tilt angle generation on the homeotropic polyimide (PI) surface using a low intensity ion beam source as a function of incident angle. An excellent LC alignment of nematic liquid crystal (NLC) on the PI surface with ion beam exposure for all incident angles was observed. The tilt angle of NLC on the homeotropic PI surface for all incident angles was from 90 to 88 degree was observed. Also the tilt angle of NLC on the homeotropic PI surface with ion beam exposure of 400 eV had a tendency to increase as ion beam energy incident angle become more instance from 45 degree. Finally, a good LC alignment thermal stability on the homeotropic PI surface with ion beam exposure can be achieved.

• Wind and Structures
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• v.23 no.1
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• pp.59-73
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• 2016

In this paper, a hyperbolic shear deformation beam theory is developed for free vibration analysis of functionally graded (FG) sandwich beams. The theory account for higher-order variation of transverse shear strain through the depth of the beam and satisfies the zero traction boundary conditions on the surfaces of the beam without using shear correction factors. The material properties of the functionally graded sandwich beam are assumed to vary according to power law distribution of the volume fraction of the constituents. The core layer is still homogeneous and made of an isotropic material. Based on the present refined beam theory, the equations of motion are derived from Hamilton's principle. Navier type solution method was used to obtain frequencies. Illustrative examples are given to show the effects of varying gradients and thickness to length ratios on free vibration of functionally graded sandwich beams.

• Structural Engineering and Mechanics
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• v.52 no.3
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• pp.595-601
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• 2014

For analysis of the plates and membranes by numerical or analytical methods, the question of choice of the system of functions satisfying the different boundary conditions remains a major challenge to address. It is to this issue that is dedicated this work based on an approach of choice of combinations of trigonometric functions, which are shape functions of a bended beam with the boundary conditions corresponding to the plate support mode. To do this, the shape functions of beam vibrations for strength analysis of the rectangular plates by Kantorovich-Vlasov's method is considered. Using the properties of quasi-orthogonality of those functions allowed assessing to differential equation for every member of the series. Therefore it's proposed some new forms of integration of the beam functions, in order to simplify the problem.