• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.472-477
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• 2004

Miniaturization is the central theme in modern fabrication technology. Many of the components used in modem products are becoming smaller and smaller. The direct write FIB technology has several advantages over contemporary micromachining technology, including better feature resolution with low lateral scattering and capability of mastless fabrication. Therefore, the application of focused ion beam(FIB) technology in micro fabrication has become increasingly popular. In recent model of FIB, however the feeding system has been a very coarse resolution of about a few ${\mu}{\textrm}{m}$. It is not unsuitable to the sputtering and the deposition to make the high-precision structure in micro or macro scale. Our research is the development of nano stage of 200mm strokes and l0nm resolutions. Also, this stage should be effectively operating in ultra high vacuum of about 1$\times$10$^{-5}$ pa. This paper presents the concept of nano stages and the discussion of the material treatment for ultra tush vacuum.

• Advances in materials Research
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• v.8 no.4
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• pp.313-335
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• 2019

The objective of the present paper is to investigate the bending and free vibration behavior of functionally graded material (FGM) sandwich rectangular plates using an efficient and simple higher order shear deformation theory. Unlike other theories, there are only four unknown functions involved, as compared to five in other shear deformation theories. The most interesting feature of this theory is that it does not require the shear correction factor. Two common types of FGM sandwich plates are considered, namely, the sandwich with the FGM facesheet and the homogeneous core and the sandwich with the homogeneous facesheet and the FGM core. The equation of motion for the FGM sandwich plates is obtained based on Hamilton's principle. The closed form solutions are obtained by using the Navier technique. A static and free vibration frequency is given for different material properties. The accuracy of the present solutions is verified by comparing the obtained results with the existing solutions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.586-588
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• 2001

Inner part of FRP specimen was made unidirectionally by pultrusion method and outer part of FRP was made by filament winding method to study the effect of fiber orientatons on the strength of FRP. The strength of bending and compression was simulated and evaluated. The results of simulated strength and evaluated strength were different greately each other. The stress which affect the feature of FRP was simulated to investigate the difference of the results between simulation and evaluation Shear stresses were investigated to the main stress to affect the fracture of FRP.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.782-784
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• 2002

Many compound semiconductors which have high carrier mobility and small band gap have attentive in application of various practical a field. Especially, InSb served for Hall device and magnetic resistor such as magnetic sensor because InSb thin film has high mobility. Many studies on InSb thin film deposition because In and Sb has been very different feature of vapor pressure($10^4$ times) When In and Sb deposited. In this paper studied it In and Sb deposited simultaneously using by method of co-sputtering deposotion. This process, get to effects of manufacture process simplification. After that this paper observed micro structure and electronic behavior of InSb thin film using by co-sputtering.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.1013-1015
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• 2002

1-(9,9-Di-octyl-fluorenyl)-2-substituted-2-cyanvinylene was synthesized and emission feature in solution are presented. Photoluminescence characteristics of 1-(9,9-Di-octyl-fluorenyJ)-2-substituted-2-cyanvinylene are measured by solvents such as carbon tetrachloride, normal hexane, chloroform, ethylaccetate, acetonitrile, methanol. It is shown that depending in the strength of the donor-acceptor internal charge transfer, and emission spectra are more or less red-shifted.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.505-508
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• 2006

Self-leveling mortar is walkable bottom mortar which can maintain the horizontality of self fluid and have the the quick-setting quality, the low-human-effort practicable material of high-quality bottom in construction. In accordance with more adhesive strength with bottom side and absorption control, Primer is used for purpose to prevent pin-hole occurrence by self leveling mortar application prior to construction. This study is composed measurement of absorption, adhesive strength. Used material is NP-40 as nonionic emulsifying agent, uses SA-210L as negative ion emulsifying agent, uses APS, SBS as ridical initiator. A result of test, in accordance with image of Primer, as low temperature and application frequency, indicates low absorption rate and adhesive strength, as solid powder and dryness time is increse, absorption rate and adhesive strength lowly shows figure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.140-140
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• 2010

There have been intensive and continuous efforts in the field of DLC coating process because of their feature, like high hardness, high elasticity, abrasion resistance and chemical stability and have been applied widely the industrial areas. In this report, tungsten carbide(WC) mold core was manufactures using high performance precision machining and the efforts of DLC coating on the surface roughness and SEM of WC mold was evaluated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.139-139
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• 2010

Rhenium-Iridium(Re-Ir) thin films were deposited onto the tungsten carbide(WC) molding core by sputtering system. The Re-Ir thin films on tungsten carbide molding core were analyzed by scanning electron microscope(SEM) and surface roughness. The Re-Ir coating technique has been intensive efforts in the field of coating process because the coating technique and process have been their feature, like hardness, high elasticity, adrasion resistance and mechanical stability and also have been applied widely the industrial and biomedical areas. In this report, tungsten carbide(WC) molding core was manufactures using high performance precision machining and the efforts of Re-Ir coating on the surface roughness.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.3
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• pp.183-189
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• 2010

In this paper, the trench gate emitter switched thyristor(EST) withl trench gate electrode is proposed for improving snap-back effect which leads to a lot of problems in device applications. The parasitic thyristor which is inherent in the conventional EST is completely eliminated in this structure, allowing higher maximum controllable current densities for ESTs. The dual trench gate allows homogenous current distribution in the EST and preserves the unique feature of the gate controlled current saturation of the thyristor current. The characteristics of the 1700 V forward blocking EST obtained from two-dimensional numerical simulations (MEDICI) is described and compared with that of a conventional EST. we carried out layout, design and process of EST devices.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.2
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• pp.289-298
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• 2003

Meshfree approximations exhibit significant Potential to solve partial differential equations. Meshfree methods have been successfully applied to various problems which the traditional finite element methods have difficulties to handle including the quasi-static and dynamic fracture, large deformation problems, contact problems, and strain localization problems. Reproducing Kernel Particle Method (RKPM) is used in this research fur to its built-in feature of multi-resolution. the sound mathematical foundation and good numerical performance. A formulation of RKPM is reviewed and numerical examples are given to verify the accuracy of the proposed meshfree method for largely deformed elasto-plastic material.