• Title/Summary/Keyword: Fiber components

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The surface mounting technology to prevent improper fine chip insertions by using fiber sensors (Fiber sensor를 이용한 미소칩 미삽 방지 표면실장기술)

  • Kim, Young-Min;Kim, Hyun-Jong;Um, Sun-Chon;Kong, Heon-Tag;Kim, Chi-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.9
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    • pp.4138-4146
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    • 2011
  • In surface mount technology, with cellular phones and flat panel displays shrinking in size, the electric goods for making these things are getting smaller as well. Therefore, the technology of mounting components such as 0402 and 0603 Chip is on the rise. The chip mount manufacturing companies have studied the mount technology to prevent the missing insertions or improper insertion. This study suggests arranging the mechanical structure by using fiber sensors to eliminate missing insertions or improper insertions and developing the technology for upgrading system algorithms.

Feasibility study on the development of respiration sensor using a chalcogenide optical fiber (Chalcogenide 광섬유를 이용한 호흡측정 센서 개발을 위한 기초 연구)

  • Yoo, Wook-Jae;Cho, Dong-Hyun;Jang, Kyoung-Won;Oh, Jeong-Eun;Lee, Bong-Soo;Tack, Gye-Rae
    • Journal of Sensor Science and Technology
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    • v.16 no.5
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    • pp.331-336
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    • 2007
  • In this study, we have fabricated an infrared optical fiber based sensor which can monitor the respiration of a patient. The design of a chalcogenide optical fiber based sensor is suitable for insertion into a high electro-magnetic field environment because the sensor consists of low cost and compact mid-infrared components such as an infrared light source, a chalcogenide optical fiber and a thermopile sensor. A fiber-optic respiration sensor is capable of detecting carbon dioxide ($CO_{2}$) in exhalation of a patient using the infrared absorption characteristics of carbon gases. The modulated infrared radiation due to the presence of carbon dioxide is guided to the thermopile sensor via a chalcogenide receiving fiber. It is expected that a mid-infrared fiber-optic respiration sensor which can be developed based on the results of this study would be highly suitable for respiration measurements of a patient during the procedure of an MRI.

A Study on the Materials and Technique of Lime Plaster Work in Government Constructions in the Late of Joseon Dynasty(17~19c) - Focused on the Lime Plaster Materials in 'Yeonggeon-Uigwe'(Construction Reports) - (조선후기 관영건축공사의 회(灰)미장재와 공법에 관한 연구 - 영건의궤(營建儀軌)의 유회(油灰), 수회(水灰), 양상도회(樑上塗灰)를 중심으로)

  • Lee, Kweon-Yeong
    • Journal of architectural history
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    • v.18 no.4
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    • pp.63-79
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    • 2009
  • Since the 1970's, UNESCO and ICOMOS have adopted or emphasized on the principles of historic preservation. One of them is what to require a repair have not to be repaired beyond the limits of the features and techniques to have been born in those days of establishment. On the premise, this paper is to examine the materials and technique of lime plaster work in order for roof ridge, and for bond paste of stones and bricks in government constructions in the late of Joseon dynasty(17~19c). The result of this examination will come up with a basic conformity in the case of repairing the building established in the late of Joseon dynasty. This paper is carried out for the proper repair and restoration of architectural cultural properties. Construction reports and other documents in those days are examined for the study. Following conclusions have been reached through the study. The components of old plaster mixtures which agglutinate stones each other were quicklime, perilla oil, and paper fiber. The components of old plaster mixtures which point joint of black bricks consisted of slaked lime, perilla oil, paper fiber, and cereal starch. These components were the same as coat surface of roof ridges. In the case of times, one of the following sand, white clay, sap of boiled elm bark was added to these components for the purpose of high efficiency. These materials and techniques which applied to plaster work of those buildings had developed in the process of making royal tombs. But these materials and techniques were quite different from the present.

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Changes in the Chemical and Functional Components of Korean Rough Rice Before and After Germination

  • Lee, Youn-Ri;Kim, Ja-Young;Woo, Koan-Sik;Hwang, In-Guk;Kim, Kyong-Ho;Kim, Kee-Jong;Kim, Jae-Hyun;Jeong, Heon-Sang
    • Food Science and Biotechnology
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    • v.16 no.6
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    • pp.1006-1010
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    • 2007
  • This study investigated changes in the chemical and functional components of germinated rough rice for the development of functional foods. The chemical components that were determined for 'Ilpum', 'Goami2', 'Keunnun', and 'Heugkwang' rough rice cultivars included dietary fiber, free sugars, free amino acids, and functional components such as tocopherols and ${\gamma}$-oryzanol. The crude protein, fat, total dietary fiber, and free sugar contents of the rough rice increased significantly after germination. The essential amino acid content was particularly increased. After the germination of the 'Ilpum', 'Goami2', 'Keunnun', and 'Heugkwang' varieties, the following increases were found: ${\gamma}$-aminobutyric acid increased 2.4, 2.5, 6.1, and 3.4 times, respectively; ${\alpha}$-tocopherol, ${\alpha}$-tocotrienols, and ${\gamma}$-tocotrienols increased significantly; and ${\gamma}$-oryzanol content increased 0.8, 1.1, 1.5, and 1.2 times, respectively. Thus, germinated rough rice has the potential to be used as a healthy and functional food ingredient.

Analysis of General Components, Mineral Contents, and Dietary Fiber Contents of Synurus deltoides (수리취(Synurus deltoids)의 일반성분, 무기질 및 식이섬유에 관한 연구)

  • Park, Min-Hee;Choi, Byoung-Gon;Lim, Sang-Hyun;Kim, Kyung-Hee;Heo, Nam-Ki;Yu, Seong-Hee;Kim, Jong-Dai;Lee, Kwang-Jae
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.40 no.11
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    • pp.1631-1634
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    • 2011
  • This study was conducted to estimate the general components, minerals, and dietary fiber contents of Synurus deltoides. S. deltoides contained 81.1% moisture content, and the proportions of crude fat, crude protein, crude ash, and crude fiber were 0.3%, 4.2%, 2.6%, and 3.5%, respectively. Potassium (3,249.1 mg) was the most abundant component among the minerals in S. deltoides. In addition, S. deltoides contained many other minerals, e.g. calcium (854.8 mg), phosphorus (60.3 mg), magnesium (344.7 mg), sodium (57.3 mg), zinc (1.7 mg), iron (30.9 mg), copper (0.8 mg), and manganese (5.8 mg). Almost all of the mineral contents of S. deltoides were higher than those of Aster scaber and Ligularia fischeri, except for zinc, copper, and manganese. Total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble dietary fiber (SDF) contents of S. deltoides were 42.6 g, 37.9 g, and 4.7 g, respectively, and these were also higher than those of A. scaber and L. fischeri used in this study. These results suggest that S. deltoides may be a valuable nutrient source.

Friction Characteristics of automotive friction materials containing different metallic fibers against Al-MMC and cast iron disk specimens (자동차용 마찰재에 사용되는 금속섬유의 종류에 따른 마찰특성의 변화에 관한 연구)

  • Lee, Jin-Soo;Jang, Ho
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1999.06a
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    • pp.255-264
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    • 1999
  • Friction characteristics of automotive friction materials containing different metallic fibers rubbing against Al-MMC and cast iron disk specimens have been studied. Friction materials containing aluminum, copper or low steel carbon fiber were tested. Friction tests were composed of three different phases to investigate the effect of temperature, pressure, speed, and drag time. The results showed that the friction material containing Al fibers has lower friction force and wear amount than the others with Cu or Steel fiber. On the other hand, the wear of friction material was severe in the case of using Al-MMC rotors. These results showed that the thermal decomposition of solid lubricants (and organic components), formation of transfer layer, and SiC particles in the AI-MMC rotor play crucial roles in determining the friction characteristics.

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An Improved Configuration for Radio over Fiber Transmission

  • Parvez, M.F.;Zhou, M.T.;Sharma, A.B.;Zhang, J.G.
    • Proceedings of the IEEK Conference
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    • 2002.07a
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    • pp.14-17
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    • 2002
  • A configuration for radio-over-fiber transmission, with remote LO delivery from the central office, and a simple, cost-effective, base station solution is proposed. It is shown that using practically available components, and even with a fiber dispersion of 17 ㎰/nm/km, it is possible to transmit, without repeaters, bit rates of up to 622 Mbit/s for about 20 km at a bit-error rate of 10$\^$-9/, with 0㏈m laser power and a modest optical gain of 6㏈. By increasing the optical gain to 25 ㏈, the link length can be increased to ∼80 km.

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Micro-mechanical Modeling of the Consolidation Processes in Titanium Metal Matrix Composites (티타늄금속기 복합재료의 강화공정에 관한 미시역학적 모델링)

  • 김준완;김태원
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.05a
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    • pp.207-210
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    • 2002
  • Metal matrix composites(MMCs) are increasingly attractive for high technology components such as aerospace applications and transportations due to their high strength, stiffness, and toughness. Many processes for fabricating MMCs have been developed, and relatively simple Foil-Fiber-Foil method is usually employed in solid state consolidation processes. During the consolidation processes at high temperature, densification occurs by the inelastic flow of the matrix materials, and the process is coupled with the conditions of pressure, temperature and volume fraction of fiber and matrix materials. This is particularly important in titanium matrix composites, and thus a generic model based on micro-mechanical approaches enabling the evolution of density over time to be predicted has been developed. The mode developed is then implemented into FEM so that practical process simulation has been carried out. Further the experimental investigation of the consolidation behavior of SiC/Ti-6Al-4V composites using vacuum hot pressing has been performed, and the results obtained are compared with the model predictions.

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The Study on Improvement of Acoustic Performance for Automobile Sound-absorbing Materials Using Hollow Fiber (중공 섬유를 이용한 자동차 흡음재 성능 향상 연구)

  • Lee, Jung-Wook;Lee, Su-Nam;Shim, Jae-Hyun;Jung, Pan-Ki;Lee, Won-Ku;Bang, Byoung-Joo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.9
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    • pp.850-857
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    • 2011
  • Generally, sound-absorbing materials in vehicles are used for giving the comfort to passengers by reducing noise while driving. Materials of which targets are light weight, high performance, eco friendliness and recycling have been developed recently. In this study, sound-absorbing materials using PET(polyethylene terephthalate) hollow fibers to achieve the light weight and the high sound absorption performance are developed, and then evaluated to meet a requirement for the automotive components. The test results show that the acoustic performances of developed products having new fiber structure are better than those of the conventional product.

Influence of Sowing Time on Growth, Yield and Nutritional Quality of Forage Rape in Spring

  • Kwon, Byung-Sun;Shin, Jeong-Sik;Park, Hee-Jin;Shin, Jong-Sup;Choi, Seong-Yu
    • Plant Resources
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    • v.6 no.1
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    • pp.11-15
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    • 2003
  • To determine as optimal sowing time of forage rape in spring time in southern areas of Korea, forage rape cv. Velox, the highest yielding variety among introduced varieties of forage rape, was grown under five different sowing times. Yield components such as plant length, number of branches and number of leaves etc. were higher at the sowing time of Mar. 15 and Mar. 25. The plants sown at Mar. 15 and Mar. 25 also showed highest fresh and dry matter yield. When plants were grown under later sowing time, they showed higher values in content of crude protein and lower values in contents of crude fiber such as Neutral Detergent Fiber (NDF), Acid Detergent Fiber (ADF), cellulose and lignin. There was no relationship between variation of In Vitro Dry matter Digestibility (IVDMD) and sowing time. The plants sown at Mar. 15 and Mar. 25 showed highest digestible dry matter yields.

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