• Title/Summary/Keyword: Compact

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Remarks on the reidemeister numbers

  • Li, Degui
    • Bulletin of the Korean Mathematical Society
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    • v.33 no.3
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    • pp.397-409
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    • 1996
  • Let X be a connected compact polyhedron and $f : X \to X$ a selfmap of X. The Reidemeister number of f is denoted by R(f).

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Coproducts of Ringed Spaces

  • Cho, Yungduk
    • Proceedings of the Korea Database Society Conference
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    • 2000.11a
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    • pp.111-115
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    • 2000
  • In this paper, we show that arbitrary family of ringed spaces has the coproduct and every finite coproduct of compact ringed spaces is compact.

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Physical Property of PTT/Wool/Modal Air Vortex Yarns for High Emotional Garment (고감성 의류용 PTT/울/모달 에어 볼텍스 복합사의 물성)

  • Kim, Hyunah
    • Journal of the Korean Society of Clothing and Textiles
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    • v.39 no.6
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    • pp.877-884
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    • 2015
  • Polytrimethylene Terephthalate (PTT) is an eco-fiber with good elastic properties; however, it requires more detailed studies related to spinnability according to blending of various kinds of fibers. The evolution of spinning technology was focused on improved productivity with good quality; in addition, air vortex spinning was recently invented and applied on the spinning factory as the facility with good productivity and quality. More detail spinning technology according to the blending of various kinds of fibers on the air vortex spinning system is required to obtain good quality yarns for high emotional fabrics. In this paper, the physical properties of air vortex, compact and ring staple yarns using PTT/wool/modal blend fibers were investigated with yarn structure to promote high functional PTT that includes fabrics for high emotional garments. Unevenness of air vortex yarns was higher than those of compact and ring yarns; in addition, imperfections were greater than those of compact and ring yarns, which was attributed to a fascinated vortex yarn structure. Tenacity and breaking strain of air vortex yarns were lower than those of compact and ring yarns, caused by higher unevenness and more imperfections of air vortex yarns compared to compact and ring yarns. Vortex yarns showed the highest initial modulus and ring yarns showed the lowest ones which results in a stiff tactile feeling of air vortex yarns in regards to the initial modulus of yarns. Dry and wet thermal shrinkages of air vortex yarns were lower than ring yarns. Good shape retention of vortex yarns was estimated due to low thermal shrinkage.

Controlled Release of Three Nutrients from Dual-layered Coated Compact Pellets (이중 코팅된 압착 펠렛으로부터 3종 영양소의 방출 제어)

  • Piao, Zong-Zhu;Lee, Eung-Seok;Choi, Yun-Jaie;Lee, Beom-Jin
    • Journal of Pharmaceutical Investigation
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    • v.38 no.3
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    • pp.177-182
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    • 2008
  • The purposes of this study were to prepare dual-layered coated compact pellets containing three nutrients Glucose, Chromium picolinate, Vitamin C) for rumen bypass. The core compact pellets were prepared by an extrusionspheronization method and then double layered coated with pH independent EC (ethyl cellulose) and pH-dependent polymers ($Eudragit^{(R)}$ E100) using a fluid-bed spray coater. Depending on the coating levels of EC and $Eudragit^{(R)}$ E100, release profiles were variable in simulated rumen (pH 6.8) and abomasums (pH 2.0) fluid using USP apparatus I (basket method). When compact pellets were coated with EC (about 10% level in inner layer) and then $Eudragit^{(R)}$ E100 (20% level in outer layer) in a dual-layered manner, rumen-bypass delivery resisting rumen fluid followed by release in abomasums fluid could possible. The friability was also satisfactory based on chewing behavior of ruminants. The dual-layered coated compact pellets showed smooth surface and distinct inner/outer layers using scanning electron microscopy (SEM). The current rumen bypass delivery system can be also applicable to deliver other nutrients in ruminants.

A Compact Tunable VCSEL and a Built-in Wavelength Meter for a Portable Optical Resonant Reflection Biosensor Reader

  • Ko, Hyun-Sung;Kim, Bong-Kyu;Kim, Kyung-Hyun;Huh, Chul;Kim, Wan-Joong;Hong, Jong-Cheol;Park, Seon-Hee;Yang, Seong-Seok;Jang, Ho-Jin;Sung, Gun-Yong
    • Journal of the Optical Society of Korea
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    • v.14 no.4
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    • pp.395-402
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    • 2010
  • This study reports a portable and precision photonic biosensor reader that can measure the concentration of a particular antigen using an optical resonant reflection biosensor (ORRB). To create a compact biosensor reader, a compact tunable vertical-cavity surface-emitting laser (VCSEL) and a compact built-in wavelength meter were manufactured. The wavelength stability and accuracy of the compact built-in wavelength meter were measured to be less than 0.02 nm and 0.06 nm, respectively. The tunable VCSEL emission wavelength was measured with the compact built-in wavelength meter, it has a fast sweep time (~ 10 seconds) and a wide tuning range (> 4 nm) that are sufficient for biosensor applications based on ORRB. The reflection spectrum of a plastic based ORRB chip was measured by the fabricated portable photonic biosensor reader using the VCSEL and wavelength meter. Although the reader is the size of a palmtop device, it could make a precise measurement of the peak wavelength on equal terms with a conventional bulky optical spectrometer.

Compact Hybrid Branch-line Couplers and Rat-Race Couplers with Periodic Stepped Stubs (주기적인 계단형 스터브를 갖는 소형화된 하이브리드 Branch-Line 결합기와 Rat-Race 결합기)

  • Lee Chang On;Kim Won-Ki;Kim Sang-Tae;Shin Chull-Chai
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.12
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    • pp.115-124
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    • 2004
  • In this paper, we introduce the advanced compact transmission line with periodic stepped stubs. They are more effective than normal stubs in ATL. The short stepped stubs loading of transmission line work as effective shunt capacitance and that was proved by equivalent circuit based on transmission line theory and quasi-static analysis. And the compact branch-line coupler and the compact rat-race coupler via proposed compact microstrip line were designed at 1.8 ㎓. They have 677 ㎟ and 913 ㎟, respectively, and they are 62% and 45% of normal design.