• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.4
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• pp.288-294
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• 2002

This paper presents the design, fabrication and characterization of a 32 by 32 electroplated micromirror array on a glass, a low cost substrate. Approaches taken in this work for the fabrication of micromachined mirror arrays include a line addressing scheme, a seamless array design for high fill factor, planarization techniques of polymeric interlayers, a high yield methodology for the removal of sacrificial polymeric interlayers, and low temperature and chemically safe fabrication techniques. The micromirror is fabricated by aluminum and the size of a single micromirror is 200 $\mu\textrm{m}{\;}{\times}200{\;}\mu\textrm{m}$. Static deflection test of the micro-mirror has been carried out and pull-in voltage of 44V and releasing voltage of 30V was found.

• Proceedings of the KIEE Conference
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• 2001.07c
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• pp.1829-1831
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• 2001

A novel multi-section power divider configuration is proposed to obtain wide-band frequency performance up to microwave frequency region. Design procedures for the proposed microwave broadband power divider are composed of a planar multi-section three-ports hybrid and a waveguide transformer design procedures. The multi-section power divider is based on design theory of the optimum quarter-wave transformer. Furthermore, in order to obtain the broadband isolation performance between the two adjacent output ports, the odd mode equivalent circuit should be matched by using the lossy element such as resistor. The derived design formula for calculating these odd mode matching elements is based on the singly terminated filter design theory. The waveguide transformer section is designed to suppress the propagation of the higher order modes such as waveguide modes due to employing the metallic electric wall. Simulation and experiment show excellent performance of multi section power divider.

• Journal of Magnetics
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• v.9 no.2
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• pp.47-51
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• 2004

Giant magneto-impedance (GMI) effect in zero-magnetostrictive Co-based amorphous ribbons samples in their as-quenched and stress-released states as well as with intentionally induced magnetic anisotropy were investigated. Magnetic and impedance properties of the samples exhibiting different anisotropy were compared and the optimum operation conditions for the studied samples from the view-point of their utilization as a sensor element have been determined. A design of a model of magnetic field sensor and characteristics of the constructed prototype are presented.

• Journal of environmental and Sanitary engineering
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• v.20 no.4 s.58
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• pp.38-44
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• 2005

Cryptand resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene divinylbenzene (DVB) copolymer with crosslink of $1\%,\;2\%,\;5\%\;and\;10\%$ by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time, dielectric constant of solvent and crosslink on adsorption of uranium$(UO_2^{2+})$ ion were investigated. The uranium ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in ethanol was in increasing order uranium$(UO_2^{2+})$ > zinc$(Zn^{2+})$ > samarium$(Sm^{3+})$ ion. The adsorption was in order of $1\%>2\%>5\%>10\%$ crosslink resin and adsorption of resin decreased in proportion to order of dielectric constant of solvents.

• Composites Research
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• v.15 no.1
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• pp.9-20
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• 2002

In this study, the design method of filament wound composite pressure tanks was established by using finite element analyses. Pressure tanks were designed with and without a load sharing metallic liner. A GUI(graphic user interface) program was developed to increase the efficiency of analyses. The replacement ratio was defined in order to replace a metal pressure tank with a composite one. Finally, the best design model that is satisfied with design requirements was suggested.

• Herbal Formula Science
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• v.12 no.1
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• pp.177-193
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• 2004

Objectives: This study has been done to compare the Haematite's composition before and after using processing method and to clarify its quality and naming through the historical herbal books. Methods: I studied the Haematite and processed Haematite using physical and chemical methods which contain microscopic analysis, X-ray diffraction analysis, thermal analysis, XRF, ICP, etc, to compare the compositions and its characters. Results: Haematite is a metallic oxide(Hematite, $Fe_2O_3$). Haematite contains a main ingredients of crude Haematite Fe 40.336% - 62.174%, processed Haematite $50.499%{\sim}62.791%$(a theory value is 69.944% the korean pharmacopoeia wants >45%) and small ingredients, also. Conclusion: A radio-element contents of U, Th contain less than average contents of the lithosphere's U 1.8ppm, Th 7.2ppm.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.330-332
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• 2003

현대 사회는 인구, 산업, 경제, 활동이 도시에 집중되어 발달되고 있으며, 도시에서의 활동증가로 인한 교통량도 급격히 증가하고 있다. 급격히 증가된 인간의 생활환경 변화로 인한 오염물질의 배출도 역시 증가하여 우리의 주변환경을 심각하게 오염시키고 있다. 대기중에 존재하는 에어로졸 입자는 자연발생원에서 직접 대기중에 배출되는 해염입자, 토양입자 등과 같은 1차 입자(Primary particle)와 주로 연소, 소각 등에 의해 인위적으로 발생된 가스상 물질의 대기중에서 다양한 물리ㆍ화학적인 반응을 통해 생성되는 2차입자(Secondary particle)로 크게 구별할 수 있다. (중략)

• Journal of environmental and Sanitary engineering
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• v.23 no.1
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• pp.57-65
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• 2008

Resins were synthesized with 1-aza-15-crown-5 macrocyclic ligand attached to styrene(dangerous matter) divinylbenzene(DVB) copolymer with crosslink of 1, 2, 6 and 15% by substitution reaction. The synthesis of these resins was confirmed by content of chlorine, element analysis, and IR-spectrum. The effects of pH, time and crosslink on adsorption of metal ion　from water fire extinguishing agent by the synthetic resin adsorbent were investigated. The metal ion was showed fast adsorption on the resins above pH 3. The optimum equilibrium time for adsorption of metallic ions was about two hours. The adsorption selectivity determined in water was in increasing order of $Mg^{2+}>Al^{3+}>Pb^{2+}$. The adsorption was in the order of 1, 2, 6, and 15% crosslink resin.

• Transactions of Materials Processing
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• v.22 no.7
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• pp.394-400
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• 2013

Microforming is a very efficient and economical technology to fabricate very small metallic parts in various applications. In order to extend the use of this forming technology for the production of microparts, the size effect, which occurs with the reduction of part size and affects the forming process significantly, must be thoroughly investigated. In this study, the tribological size effect in microforming was studied using modeling and scaled ring compression experiments. A micro-scale friction approach based on the slip-line field theory and lubricant pocket model was used to understand the friction mechanism and explain the tribological size effect. Ring compression tests were performed to analyze the interfacial friction condition from the deformation characteristics of the ring specimens. In addition, finite element analysis results were utilized to quantitatively determine the size-dependent frictional behavior of materials in various process conditions. By comparing theoretical results and experimental measurements for different size factors, the accuracy and reliability of the model were verified.

• Journal of the Korean Graphic Arts Communication Society
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• v.29 no.3
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• pp.17-30
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• 2011

The polarizer is an important optical element used in a variety of applications. Nano-wire grid polarizers in the form of sub-wavelength metallic gratings are an attractive alternative to conventional polarizers, because they provide high extinction ratio. This study has been carried out to fabrication of the 17inch area size nano-wire grid polarizer(NWGP) The master for NWGPs with a pitch of 200nm and the area size $730mm{\times}450mm$ were fabricated using laser interference lithography and aluminum sputtering and wet etching. And The NWGP fabrication process was using by the Roll to-Roll UV imprinting and was applied to flexible PET film. The results were a transmission of light (Tp) 46.7%, reflectance (Rs) 40.1% and Extinction ratio of above 16 for the visible light range.