• Title/Summary/Keyword: high quality factor

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Integrated Quality Model of Product, Service and CSR of the Consumer Coopertive in Korea (유통업의 제품, 서비스, CSR 통합 품질 모형: 소비자생활협동조합을 중심으로)

  • Huh, Kwangjin;Lee, Junkyum;Park, Sangsun
    • Korean small business review
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    • v.43 no.4
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    • pp.95-115
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    • 2021
  • Quality is an important factor influencing organizational performance, so it should be possible to accurately and effectively measure the quality perceived by members. The Consumer Cooperative can be seen as a retail industry by industry classification, and there are various studies based on the dimension of retail quality, but compared to the general retail industry, few studies have been conducted based on the quality level perceived by members. The purpose of this study is to develop quality dimensions and sub-attributes by analyzing in detail and elaborately how the quality of cooperative is viewed from the perspective of members who are both consumers and owners. To this end, the quality dimension of cooperative quality is needed to be newly developed and quality components are demonstrated based on previous studies on the quality dimension. The quality dimension of the cooperative was developed through prior research to suit the value of the cooperative in product, service, and social responsibility, and a survey was conducted to demonstrate the four major cooperative members in Korea. Through this, sub-dimensions were constructed and the quality dimension of the high-order model was demonstrated through exploratory factor analysis and confirmatory factor analysis. It aims to discover key management elements in terms of quality management and provide practical implications to management.

A Study for Frequency Characteristics of Solenoid-Type RF Chip Inductors (크기에 따른 솔레노이드 형태 RF 칩 인덕터의 주파수 특성 연구)

  • Kim, Jae-Wook
    • Journal of IKEEE
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    • v.11 no.4
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    • pp.145-151
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    • 2007
  • In this work, small-size, high-performance solenoid-type RF chip inductors utilizing a low-loss ${Al_2}{O_3}$ core material were investigated. The size of the chip inductors fabricated in this work were $0.86{\times}0.46{\times}0.45m^3$, $1.5{\times}1.0{\times}0.7m^3$, $2.1{\times}1.5{\times}1.0m^3$, and $2.4{\times}2.0{\times}1.4m^3$ and copper (Cu) wire with $27{\sim}40{\mu}m$ diameter was used as the coils. High frequency characteristics of the inductance, quality factor, and impedance of developed inductors were measured using an RF Impedance/Material Analyzer (HP4291B with HP16193A test fixture). It was observed that the developed inductors with the number of turns of 7 have the inductance of 13 to 100nH and exhibit the self-resonant frequency (SRF) of 6.4 to 1.1GHz. The SRF of inductors decreases with increasing the inductance and the inductors have the quality factor of 50 to 80 in the frequency range of 300MHz to 1.3GHz. In this study, small-size solenoid-type RF chip inductors with high inductance and high quality factor were fabricated successfully.

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Assessing the Green Total Factor Productivity of Water Use in Mainland China

  • Ning, Meng;Wu, Zheru;Zhou, Zhitian;Yang, Duogui
    • International Journal of Computer Science & Network Security
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    • v.21 no.1
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    • pp.201-206
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    • 2021
  • The significance of high-quality development and green total factor productivity has attracted widespread attention and research, while few studies on green total factor productivity that considers the use of water resources have been conducted in the context of water shortages and water stress. In this study, the green total factor productivity of water use from 2005 to 2015 in mainland China is evaluated based on the global Malmquist-Luenberger productivity index. Results show that: (1) China's green total factor productivity of water use has been improving since 2005 with an annual global Malmquist-Luenberger productivity index of 1.0104. (2) At the regional level, the eastern zone in mainland China owns the highest green total factor productivity of water use, while that in the intermediate zone ranks last. (3) The green total factor productivity of water use in the southern region (1.0113) significantly higher than that in the northern region (1.0095), and also higher than the national average level in the same period. BPC index has been the most important incluencing factor of green total factor productivity of water use at both national level and regional level since 2011.

The Evaluation of the Water Quality in Coastal Boundary on Tidal flat (통계분석기법을 이용한 전남 갯벌 해역 수질특성)

  • Jun, Sue-Kyung;Kim, Chong-Ki;Kim, Yun
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.14 no.1
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    • pp.1-10
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    • 2011
  • To understand characteristics of the water quality on the coastal boundary on tidal flat, field observations between 2008 and 2009 were undertaken twice a month at five coastal areas (Muan bay, Tando bay, Hampyeong bay, Shinan Jido and Yeongkwang coastal areas). Yearly water temperature difference was large with the range between $1.3^{\circ}C$ and $31.1^{\circ}C$. Salinity was about 32 but was the lower less than 20 for the heavy rainfall season. DO was high in winter and low in summer according to the variation of water temperature. pH represented the variation similar to DO. Suspended solid was averagely high over 100 mg/l in Yeongkwang coastal area, especially. COD did not revealed large variation with the value of about 1 mg/l. DIN and DIP concentration were high when freshwater was highly input in summer. DIN concentration was low for winter and early spring but DIP concentration did not show the seasonal variation with the continuous increase from July 2009 to December 2009. Chlorophyll a appeared high for spring with approximately $10\;{\mu}g/l$ and was higher for summer in Yeongkwang coastal area than other sites. The results of principal component analysis conducted to compare the characteristics of water quality observed in study areas showed the distinguishable features as follows. The freshwater input fluctuation appeared as the first factor in Muan and Tando bays, and the change of water temperature was the first factor in Shinan Jido and Yeongkwang coastal areas. The influence mixed with the variation of freshwater outflow and the change of water temperature in Hampyeong bay was to be the first factor.

Dependence of Q Factor on Surface Roughness in a Plasmonic Cavity

  • Kim, Yoon-Ho;Kwon, Soon-Hong;Ee, Ho-Seok;Hwang, Yongsop;No, You-Shin;Park, Hong-Gyu
    • Journal of the Optical Society of Korea
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    • v.20 no.1
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    • pp.188-191
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    • 2016
  • We investigated surface-roughness-dependent optical loss in a plasmonic cavity consisting of a semiconductor nanodisk/silver nanopan structure. Numerical simulations show that the quality factors of plasmonic resonant modes significantly depend on the surface roughness of the dielectric-metal interface in the cavity structure. In the transverse-magnetic-like whispering-gallery plasmonic mode excited in a structure with disk diameter of 1000 nm, the total quality factor decreased from 260 to 130 with increasing root-mean-square (rms) surface roughness from 0 to 5 nm. This quantitative theoretical study shows that the smooth metal surface plays a critical role in high-performance plasmonic devices.

Improvement of the Lathe Tool-post for the Suppression of Chatter. (채터 발생억제를 위한 선박 공구대의 개선에 관한 연구)

  • Jeong, Jun-Gi
    • Journal of the Korean Society for Precision Engineering
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    • v.7 no.1
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    • pp.53-62
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    • 1990
  • High speed and heavy cutting performed for improving the surface quality and productivity, are often prevented due to chatter phenomena. Chatter is a violent relative vibration between workpiece and tool in machining of metals, and is an important limiting factor of production rate and surface quality, and reduces the tool life and the dynamic performance of machine tool itself. In this study, in order to suppress the chatter, a modified tool-post combined with the spring and damper was designed and used in the actual cutting test. The results of this study are summerized as follows; The spring and damper adopted in the modified tool-post have the suppressing effects of chatter, and there exists an optimum combination between spring constant and damping ratio.

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The Regional Characteristics of Nonpoint Source Pollutant Loads in Mid-stream of Nakdong River (낙동강 중류유역의 지역별 비점오염 특성)

  • Son, Seong-Ho;Choe, Gyeong-Suk
    • KCID journal
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    • v.14 no.2
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    • pp.181-193
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    • 2007
  • The characteristics of non-point source pollutant loads in middle-stream of Nakdong River Were studied through analysis of pollutant loads of 8 sub-watersheds divided based on administrative district. The pollutant concentration of each sub-watershed was collected from Nakdong-River Water Research Institute and Daegu Regional Environmental Office, respectively. Pollution items analysed in this study were BOD, SS, T-N and T-P. High degree of non-point pollution was observed from Gumi, Goryeong, Gyeongsan, Daegu and Sungju, and pollution was usually increased during rainy season. This result indicates that a given pollution condition within the watershed can be more sensitive than location factor to the level of water quality. The main sources of non-point pollution were population and livestock, as well as landuse factor, and were found to significantly contribute to the water pollution. Alternative solutions for controlling pollution sources, therefore, should be provided to meet target levels of water quality in this region.

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The Effects of Non-Stoichiometry and Sintering Temperature on the Magnetic Properties of Ni-Zn Ferrites (비양론 화학적 조성 및 소결온도가 Ni-Zn Ferrite 의 자기적 성질에 미치는 영향)

  • 박준철;임호빈
    • Journal of the Korean Ceramic Society
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    • v.17 no.2
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    • pp.89-95
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    • 1980
  • The effect of non-stoichimetry and sintering temperature on the magnetic properties of materials in the system $Ni_{0.39}Zn_{0.61}Fe_{2.0+x}O_4$ have been investigated. The value of x used in initial weighing of oxides were varied from -0.04 to -0.12. The value of x, however, appears to be from +0.04 to -0.04 after ferrite powder preparation due to iron pick up during ball mill mixing and grinding. The densities of specimens which were deficientinrion were higher than those with excess ion. Specimens with near stoichiometric composition showed maximum initial permeability an dminimum coercivity whereas high values of quality factor (Q) were observed in iron deficient specimens. The quality factor decreased monotonically with increasing sintering temperature, but the permeability showed maxima with increasing sintering temperature. Thus highest value of figure of merit $\mu$Q was obtained in composition $Ni_{0.39}Zn_{0.61}Fe_{1.98O4}$ sintered at 100$0^{\circ}C$ for 3 hrs. in an air atmosphere.

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Characteristic Analysis of Spiral Type Thin-Film Inductor Using Finite Element Method (유한요소법을 이용한 스파이럴 박막인덕터의 특성해석)

  • Ha, Gyeong-Ho;Hong, Jeong-Pyo;Song, Jae-Seong;Min, Bok-Gi;Kim, Hyeon-Sik
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.48 no.11
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    • pp.617-624
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    • 1999
  • The spiral type thin-film inductor performed in high frequency at 2-5[MHz] range is analyzed by 2-dimensional Finite Element Method(2D FEM). The features of micro thin-film inductor have complicated electromagnetic phenomenon such as skin effect, proximity effect and magnetic saturation. To develope miniatured magnetic device considering these features, it is important to predict the property of the thin film inductor according to design parameter. In this paper, we present the 2D FEM analysis for the spiral type thin film inductor. The characteristics of inductor from point of view of inductance, resistance and quality factor are studied according to design parameter and various pattern construction.

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Microstructural and Piezoelectric Characteristics of PSN-PMN-PZT Ceramics Produced by Attrition Milling

  • Juhyun Yoo;Sukkyu Min;Jaeil Hong;Sungjae Suh;R, Soonchul-U
    • Transactions on Electrical and Electronic Materials
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    • v.2 no.3
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    • pp.18-23
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    • 2001
  • For the piezoelectric transformer application, Pb(Sb$\_$1/2/ Nb$\_$1/2/)O$_3$-Pb(Zr,Ti)O$_3$ ceramics were produced by attrition milling. Microstructural, dielectric and piezoelectric characteristics of the ceramics were investigated as a function of milling time. The particle size and grain size decreased while dielectric constant, density and mechanical quality factor (Q$\_$m/) increased with milling time. Temperature coefficient of resonant frequency (TCf$\_$r/) was shifted to positive side with increasing milling time. The attrition milling process proved to be one of the effective routes to produce transformers for high power application.

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