• 제목/요약/키워드: center gap

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고주파 신호전송을 위한 고투자율 자심재료의 특성 (Properties of High Permeability Magnetic Materials for Signal Transmission at the High Frequency)

  • 김현식;김종령;김기욱;이준희;변우봉;박병석;이태영
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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    • pp.272-273
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    • 2005
  • 전력선 통신을 위한 커플러용 자심재료의 열처리 온도증가에 따라 결정이 성장하여 인덕턴스는 증가 하였고, $550^{\circ}C$ 이상에서는 포화점을 나타내었다. 커플러는 자심재료의 투자율이 높을수록 커플러의 저주파 대역의 신호전승 특성이 우수하게 나타났지만, 주파수 증가에 따라 급격히 저하하는 불안정한 특성을 나타내었다. 그리고 절단면 사이의 Air gap 증가에 따라 10 MHz이하의 주파수 대역에서 신호전승특성이 급격히 감소하였고, 허용전류는 직선적으로 증가하였으며 Air gap이 $600{\mu}m$이상일 때 300A의 전류에서 특성을 발휘하였다.

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Social Expectations, Personal Values, and Women's Role in South Korea

  • Cho, Sung Kyum;LoCascio, Sarah Prusoff
    • Asian Journal for Public Opinion Research
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    • 제5권3호
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    • pp.175-191
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    • 2018
  • This exploratory study considers the difference between personal and perceived societal values related to South Korean women's role in the home, workplace, and society using eight items asked on the Korean Academic Multimode Open Survey (KAMOS), May-July 2017. Factor analysis showed that these eight items could be grouped into two categories: women's role in her family and women's in the outside world. Of the 2,000 respondents, 54.1% personally agreed that "Both the husband and wife should contribute to their family income." People in their 30s felt the largest gap between their personal and societal values; women also felt a larger gap than men. Those who watched television more were generally more conservative than those who used the Internet more. People who felt a smaller gap between societal and personal values were more likely to feel proud to be a Korean citizen. People who believe that it is better not to marry felt a bigger gap between some societal and personal values on items relating to whether a wife should work, whether a woman's housework or paid job is more valuable, and whether women's job performance is equal to men's. People who believe that divorce is sometimes acceptable were also more likely to feel a bigger difference in two items: the item about job performance and an item about whether a married woman's social status is dependent on her husband's.

Glycidyl Azide Polymer를 포함하는 에너지화 열가소성 폴리우레탄의 합성 및 성질 (Synthesis and Properties of Energetic Thermoplastic Polyurethane included Glycidyl Azide Polymer)

  • 김형석;유종성;권정옥;노시태;권순길;이정환;유재철;최근배
    • 한국군사과학기술학회지
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    • 제12권5호
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    • pp.660-666
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    • 2009
  • Thermoplastic polyurethane elastomer(PU-TPE) and energetic thermoplastic polyurethane Elastomer(E-PU-TPE) were prepared from Hexamethylene diisocyanate(HDI), 1,4-BD/AA ester polyol and glycidyl azide polymer(GAP-2400) as an energetic material by the addition polymerization. The PU-TPE and E-PU-TPE were characterized by FT-IR and GPC. Viscometer, DSC and UTM were used to investigate the viscose behavior with a various solvent, thermal properties and mechanical properties of PU-TPE and E-PU-TPE, which are of potential interest for the development of high performance binder of energetic solid propellants. It was found that $M_w$ of PU-TPE and E-PU-TPEs are over 100,000 and decreased with increase of GAP-2400 contents. $T_m$ and ${\Delta}H$ as thermal properties decreased and also tensile strength and elongation at break as mechanical properties decreased with increase of GAP-2400 contents.

유량변화와 지류유입에 따른 금강의 수질 변화 (Influence of River Discharge Fluctuation and Tributary Mixing on Water Quality of Geum River, Korea)

  • 심무준;이수형
    • 한국물환경학회지
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    • 제31권3호
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    • pp.313-318
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    • 2015
  • To study the influence of changes in river discharge on water quality of the main stem of the Geum River, we investigated variation of inflow load from tributaries with river discharge. We also studied the mixing behavior of pollutants during mixing of waters of the main stem and Gap Stream. For this study, we collected water quality data such as suspended solids (SS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), total nitrogen (TN) and total phosphorus (TP) representing pre-monsoon, monsoon, and post-monsoon events of 2013 from a website of Water Information System. Based on inflow load, the Gap and Miho streams may be ones of tributaries which may largely influence water quality of main stem in upper river region. The Suksung and Nonsan Streams seemed to further affect water quality downstream. Results of modified EMMA indicated SS and TP may have another source(besides Gap Stream) at pre-monsoon, monsoon, and post-monsoon period. In contrast, TN and organic matter (BOD, COD, TOC) were conservative at pre-monsoon and post-monsoon. However, when river discharge increased, these pollutants may also came from unspecified non-point sources. Therefore, we need to attempt to find non-point sources for the pollutants in the main channel of upper Geum River region.

송전선로 EMI 특성 실험용 인공잡음발생장치 설계, 제작 및 적용 (The Design, Manufacture and Applications of a Gap Noise Generator for Testing the Characteristics of EMI from Transmission Lines)

  • 주윤로;양광호;명성호;이동일;신구용
    • 대한전기학회논문지:전력기술부문A
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    • 제51권1호
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    • pp.23-28
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    • 2002
  • In order to survey the radiation characteristics of pure line noise of unwanted noise from overhead high voltage AC transmission lines, a disk type gap noise generator was manufactured. Disk size which decides capacitance between the noise generator and earth was selected through preliminary indoor experiments and analysis by using surface charge method. The capacitance is one of principal parameters related to the injection of a proper noise current into lines. On the basis of the capacitance obtained from calculation, 5mm of space was given to the gap of the noise generator to be installed o test line and an aluminum disk of 60cm radius was made. The field experiments were performed with the noise generator hung on the Kochang 765 kV full scale test line. As the results, the useful data which can be used to analysis the radiation characteristics of noise from transmission lines were obtained. Those are the directivity of antenna toward the line, lateral profiles, frequency spectra, height pattern and so on.

MIAB용접에서 코일에 의한 자속밀도 분포의 수치적 해석에 관한 연구 (A Study on the Numerical Analysis of Magnetic Flux Density by a Solenoid for MIAB Welding)

  • 최동혁;김재웅
    • 한국정밀공학회지
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    • 제18권12호
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    • pp.73-81
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    • 2001
  • The MIAB welding uses a rotating arc as its heat source and is known as an efficient method fur pipe butt welding. The arc is rotated around the weld line by the electro-magnetic force resulting from the interaction of arc current and magnetic field. The electro-magnetic force is affected by magnetic flux density, arc current, and arc length. Especially, the magnetic flux density is an important factor on arc rotation and weld quality. This paper presents a 2D finite element model for the analysis of magnetic flux density in the actual welding conditions. The magnetic flux density is mainly dependent on gap between two pipes, the position of coil from gap center, exciting current, and relative permeability. Thus, the relations between magnetic flux density and main factors were investigated through experiment and analysis. Experiments were performed for the steel pipes(48.1mm O.D and 2.0mm thickness). The analysis results of magnetic flux density reveal that it increases with increasing exciting current, increasing relative permeability, decreasing distance from gap center to coil, and decreasing gap size. It is considered that the results of this study can be used as important data on the design of coil system and MIAB welding system.

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Planetary 형 반응기에서 웨이퍼와 기판 사이의 틈새가 웨이퍼 온도에 미치는 영향에 대한 연구 (Numerical Study on Wafer Temperature Considering Gap between Wafer and Substrate in a Planetary Reactor)

  • ;정종완;임익태
    • 반도체디스플레이기술학회지
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    • 제16권3호
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    • pp.1-7
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    • 2017
  • Multi-wafer planetary type chemical vapor deposition reactors are widely used in thin film growth and suitable for large scale production because of the high degree of growth rate uniformity and process reproducibility. In this study, a two-dimensional model for estimating the effect of the gap between satellite and wafer on the wafer surface temperature distribution is developed and analyzed using computational fluid dynamics technique. The simulation results are compared with the results obtained from an analytical method. The simulation results show that a drop in the temperature is noticed in the center of the wafer, the temperature difference between the center and wafer edges is about $5{\sim}7^{\circ}C$ for all different ranges of the gap, and the temperature of the wafer surface decreases when the size of the gap increases. The simulation results show a good agreement with the analytical ones which is based on one-dimensional heat conduction model.

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Good Agriculture Practice (GAP) and Sustainable Resource Utilization of Chinese Materia Medico

  • Wenyuan Gao;Wei Jia;Hongquan Duan;Luqi Huang;Xiaohe Xiao;Peigen Xiao;Peak, Kee-Yoeup
    • Journal of Plant Biotechnology
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    • 제4권3호
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    • pp.103-107
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    • 2002
  • The Good Agriculture Practice (GAP) program, being established in China, is an optimal way for the sustainable utilization of the medicinal plant and animal resources. Most frequently used Chinese materia medica will be mainly produced from the GAP bases in the future. To assure the successful operation of GAP program, standard operating procedure (SOP) should be implemented for specific plants or animals. Both GAP and SOP include the requirements in many aspects from the ecological environment of cultivation place, germplasm and varieties, seedling and transplant, fertilization, irrigation, and field care, to harvest and process, package, transport and storage. As a complex system, GAP demands strong commitment from the pharmaceutical industry, local administrative involvement, long term R&D support, and years of time of development before a satisfactory result can be achieved.

VA Mode의 LCOS에서 Cell Gap의 변화에 따른 전기광학적 특성 (Electro-optical Characteristics of VA mode LCOS depending on Cell Gap)

  • 강정원;손홍배
    • 반도체디스플레이기술학회지
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    • 제7권3호
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    • pp.41-43
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    • 2008
  • The electro-optical characteristics of the Liquid Crystal on Silicon (hereinafter "LCOS") micro-display on vertically alignment (VA) mode were studied depending on various cell gaps. 5 different cell gaps, such as $1.4{\mu}m,\;1.8{\mu}m,\;2.1{\mu}m,\;2.4{\mu}m$ and $2.8{\mu}m$, were selected. The reflectance-voltage (R-V) characteristics, distributions of reflected light and reflectance were calculated with 3-dimmensional LC code. At the center of cell, the smallest $1.4{\mu}m$ cell gap showed the lowest reflectance and the largest $2.8{\mu}m$ cell gap showed the highest reflectance due to the surface anchoring effect. In case of $2.1{\mu}m$ cell gap, the sum of reflectance overall cell was the highest value. Considering the reflectance and RV curve characteristic, the optimized cell gap was $2.1{\mu}m$.

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