• Proceedings of the Korean Magnestics Society Conference
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• 2016.11a
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• pp.201-201
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• 2016

• Proceedings of the Korean Magnestics Society Conference
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• 2016.11a
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• pp.202-202
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• 2016

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.161-161
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• 2006

New polymeric and oligomeric OTFT materials containing fused aromatics such as anthracene and naphthalene have been designed, synthesized and characterized. The new OTFT materials were prepared by palladium-catalyzed Suzuki cross-coupling reaction. The obtained materials were characterized by various spectroscopic methods such as UV-vis, PL, cyclovoltametry, and XRD. The obtained OTFT materials containing fused aromatics showed high thermal stability above $350^{\circ}C$ In OTFT devices using new materials, high charge carrier mobility and on/off ratio were observed.

• The Journal of the Korean dental association
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• v.54 no.7
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• pp.542-550
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• 2016

Recent technological advance have greatly expanded the application of invisible orthodontic treatment using clear thermoplastic materials. However, the final outcomes using clear aligner system do not achieve the level of final goal frequently, which results in case refinement, midcourse correction, or fixed orthodontic treatment. Therefore, mechanical properties of thermoplastic materials should be considered to improve the quality of outcomes. The purposes of this special article were to evaluate the force and stress depending on the materials, deflection and thickness of thermoplastic materials and to evaluate the mechanical properties of thermoplastic materials after repeated loading. Thickness and amount of deflection rather than products and materials showed the largest effect on force and stress. In all products, at least 159 gf of force was required for more than 1.0 mm deflection or when materials with 1.0 mm thickness were deflected. Orthodontic forces delivered by thermoplastic materials depend on the materials, thickness, amount of activation, and intra-oral condition. Proper thickness of thermoplastic materials and deflection level of tooth movement should be decided for the efficient and physiologic tooth movement.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.26.1-26.1
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• 2009

A simple route of external mechanical force is presented for enhancing the electrical properties of polymer nanocomposite consisted of nanowires. By dispersing ZnO nanowires in polymer solution and drop casting on substrates, nanocomposite transistors containing ZnO nanowires are successfully fabricated. Even though the ZnO nanowires density is properly controlled for device fabrication, as-cast device doesn't show any detectable currents, because nanowires are separated far from each other with the insulating polymer matrix intervening between them. Compared to the device pressed at 300 kPa, the device pressed at 600 kPa currents increased by 50times showing the linear behavior against drain voltage and exhibits promising electrical properties, which operates in the depletion mode with higher mobility and on-current. Such an improved device performance would be realized by the contacts improvement and the increase of the number of electrical path induced by external force. This approach provides a viable solution for serious contact resistance problem of nanocomposite materials and promises for future manufacturing of high-performance devices.

• Bulletin of the Korean Chemical Society
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• v.34 no.1
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• pp.112-116
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• 2013

Surface modification of montmorillonite (MMT) with 3-glycidoxypropyl trimethoxysilane (3GTO) in mild methanol/water mixture has been investigated in detail. The influence of reaction conditions (including silane concentration in feed, reaction time and reaction temperature) on the grafting amount and yield of silane, and further on the grafting pattern of silanes was studied by thermogravimetric analysis, elemental analysis, X-ray diffraction (XRD) and BET. Higher silane concentration, longer reaction time and higher reaction temperature are all benefit to higher grafting amount. When the grafting reaction was performed with 3 mmol/g silane concentration, at $90^{\circ}C$ for 24 h, the grafted amount and yield of silane reached 1.4443 mmol/g and 30%, respectively. Based on the XRD and BET data analysis, a speculation that the grafting pattern of silanes was concentration dependence was proposed.

• Journal of the Korean Society of Costume
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• v.41
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• pp.117-138
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• 1998

This study can be divied into three major sections: 1. Background on the 1980s : The 1980s can be characterized as a era of rising expectations over the quality of life. Interest in art, history, culture, and new technology increased to appeal to a greater audience. In fashion, these changes led to greater focus on quality and unique stylishness as fashion represented a medium through which luxury and refined tastes could be expressed. 2. Textile Trends of the 80s Divided into 4 Periods : The period of 1980-82 saw the mixture of natural lines with constructive lines. The textiles used in fashions in this period can be characterized by natural materials, mannish materials of the 1950s, feminine materials of the 1920s and 30s, and spoty materials of the 1960s. The period of 1983-85 was an avante garde period which used rustic avante-garde materials and art craft materials. The period of 1986-87 can be described as minimalistic and neo-classical which incorporated materials which represents a metropolitan feel, retro decorative materials and sporty, futuristic mat-erials. Lastly, the period of 1988-89 produced ethnic and natural fashions which relied on traditional British materials, country elegant and innocent look fabrics, ethinic and ecology-minded materials, in addition to comfortable and sports casual materials. 3. Characteristrics and methods of expression for textiles in the 1980s, : In the 1980s, the development of textiles have can be divided into 4 distinct patterns: decorative materials, sporty materials. In generals textiles have increased in their decorative nature-especially decoration by texure. Textile have also incorporated the mixture of contrasting themes in order to create new fabrics.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.95.1-95
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• 1998

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.60.1-60.1
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• 2008

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.175-175
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• 2006

Considering the number of chemosensors that have been developed for the sensing of metal ions, only a few chemosensors for fluoride anion have been described in the literature that are based on fluorescent or chromogenic responses. We performed colorimetric anion sensing based on the binding of anion analytes with hydrogen donor group in polymer backbone resulting in naked-eye color change and fluorescent quenching. Our challenges using hydrogen donor moiety was designed effectively are continuing in order for high selectivity and sensitivity for ultimate applications such as fluid solution sensing in biomolecules and gas vapor sensing.