• Journal of the Korean Vacuum Society
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• v.7 no.s1
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• pp.149-155
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• 1998

The linear electro-optic (EO) effect is one of the second-order nonlinear optical effects existing in a noncentrosymmetric macroscopic system. In a polymer thin film, the noncentrosymmetry is achieved by electric field poling. The magnitude of the linear EO response is determined through the orientational distribution function of hyperpolarizable molecular dipoles. The relation between the linear EO coefficient and the second-order nonlinear optical susceptibility is explained. Three different methods of measuring the linear EO coefficient of a poled nonliner optical polymer thin film are introduced and discussed. All of them make use of the interferometric technique, the difference being in the optical parameters which are interfering.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.10a
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• pp.77-83
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• 1998

This study is object to thermal analysis of continuous casting mold. A two-dimensional transient finite element model was developed to compute the temperature distribution and stress behavior for continuous casting mold. For thermal analysis using analysis result from FEM code. In other to thermal analysis of continuous casting mold, many variables such as casting speed, cooling condition, film coefficient, convection and load condition re considered.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.287-292
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• 1999

This study is object to thermal analysis of continuous casting nickel-coated mold. A two-dimensional transient finite element model was developed to compute the temperature distribution and stress behavior for continuous casting nickel-coated mold. For thermal analysis using analysis result from FEM code. In other to thermal analysis of continuous casting nickel-coated mold, many variables such as casting speed, cooling condition, film coefficient, convection and load condition are considered.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.6
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• pp.43-49
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• 1999

This study is object to thermal analysis of continuous casting mold. A two-dimensional transient finite element model was developed to compute the temperature distribution and stress behavior for continuous casting mold. For thermal analysis using analysis result from FEM code. In order to thermal analysis of continuous casting mold, many variables such as casting speed, cooling condition, film coefficient, convection and load condition are considered.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1999.10a
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• pp.281-286
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• 1999

This study is object to structural analysis of continuous casting mold. A two-dimensional finite element model was developed to compute the temperature distribution, stress and strain behavior for continuous casting mold. For structural analysis using thermal analysis result from FEM code. In other to structural analysis of continuous casting mold, many variables such as casting speed, cooling condition, film coefficient, convection and load condition are considered.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.181-187
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• 2000

This study is object to structural analysis comparison of continuous casting mold. A two-dimensional finite element model was developed to compute the temperature distribution, thermal stress and thermal strain behavior for continuous casting mold. For structural analysis using thermal analysis result from ANSYS. In other to structural analysis of continuous casting mold, many variables such as casting speed, cooling condition, film coefficient, convection and load condition are considered.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.200-205
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• 2000

This study is object to thermal analysis comparison of continuous casting mold. A two-dimensional transient finite element model was developed to compute the temperature distribution for continuous casting mold. For thermal analysis using analysis result from ANSYS. In other to thermal analysis of continuous casting mold, many variables such as casting speed, cooling condition, film coefficient, convection and load condition are considered.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.913-917
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• 2003

In the electronic components and devices fabrication, thin film resistors with low TCR(temperature coefficient of resistance) and high precision have been used over 3 GHz microwave in recent years. Ni-Cr alloys thin films resistors is one of the most commonly used resistive materials because it has low TCR and highly stable resistance. In this work, we fabricated thin film resistors using Evanohm alloys target(72Ni-20Cr-3Al-4Mn-Si) of s-type with excellent resistors properties by RF-sputtering. Also we reported best deposited conditions of thin film resistors for microwave to observe microstructure and electronic properties of thin film according to deposited conditions(between target and substrate, power supply)

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.11
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• pp.1880-1888
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• 2010

This study was a preliminary investigation of the influence of surface characteristics of substrates on the detergency of particulate soil. A PET film was surface modified with NaOH and DMF for different times. The surface morphology of the film was scanned by AFM and the surface energies were calculated from the measured contact angles between several solutions and film based on a geometric mean and the Lewis acid base method. The surface morphology of the PET film treated with NaOH and DMF became more etched and swelled with an increased treatment time, respectively. The surface roughness and surface area of film treated with NaOH enlarged with increased treatment time. However, the coefficient of friction of film treated with NaOH and coefficient of friction, surface roughness, and surface area of film treated with DMF increased and then decreased with increased treatment time. The contact angle of film treated with DMF decreased with increased treatment time in water and surfactant solution; however, the effect of treatment time on the contact angle was different in both solutions for film treated with NaOH. By the treatment of PET film with NaOH and DMF, the polar group of the surface energy increased and the nonpolar group decreased; however, the change of total surface energy was not significant.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.12
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• pp.1062-1070
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• 2016

The heat transfer and flow characteristics of gas turbine blade tip were investigated in this paper by using the conjugate heat transfer analysis. The rotor inlet boundary condition profile which was taken from the first stage nozzle outlet was used to analyse. The profile contained the velocity and temperature information. This study presents the influence of tip clearance about aerodynamic loss, heat transfer coefficient and film cooling effectiveness with the squealer tip designed blade model which tip clearance variation range from 1% to 2.5% of span. Results showed that the aerodynamic loss and the heat transfer coefficient were increased when the tip clearance was increased. Especially when the tip clearance was 2% of the span, the average heat transfer coefficient on the tip region was increased obviously. The film cooling effectiveness of tip region was increasing with decreasing of the tip clearance. There was high film cooling effectiveness at cavity and near tip hole region.