• 제목/요약/키워드: Quality Factor(Q)

검색결과 459건 처리시간 0.026초

위상특성을 이용한 공진기의 외적 양호도(Qe) 추출 방법 (Extracting Method of External Quality Factor(Qe) Using Phase Response)

  • 박영배;김기래
    • 한국정보통신학회논문지
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    • 제15권10호
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    • pp.2065-2071
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    • 2011
  • 본 논문에서는 마이크로스트립 선로 공진기와 입출력 단자의 결합 위치에 따른 공진기의 외적 양호도를 위상 특성을 이용하여 구하는 방법을 제시한다. 마이크로파 필터 설계에서 단자 접속 구조로 많이 이용되는 접합 선로 구조와 결합 선로 구조에 대해 단자의 위치와 선로의 폭과 간격에 따른 결과를 제시한다. 이 방법으로 정확한 $Q_e$ 값을 얻을 수 있었고, 이 결과는 결합공진기 필터 설계에 응용될 수 있다.

S-parameter circle fit 방법과 Lorentzian fit 방법으로 측정된 고온초전도 유전체 공진기의 Unloaded Quality Factor 비교 (Comparative Study for the Unloaded Quality Factors of High-Tc Superconductor-Dielectric Resonators Measured by Using S-parameter Circle-fit Method and Lorentzian-fit Method)

  • 김민정;이재훈;박은규;양우일;정호상;최윤옥;이상영
    • Progress in Superconductivity
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    • 제8권2호
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    • pp.143-151
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    • 2007
  • Accurate measurements of the microwave surface resistance (Rs) of high temperature superconductor (HTS) films are important with regard to applications of HTS materials for wireless communications. As the surface resistance values of HTS films are usually extracted from the measured unloaded quality factor ($Q_0$) of resonators made of HTS films, it is essential to measure the resonator $Q_0$ with accuracy. The $TE_{011}\;mode\;Q_0$ of sapphire resonators with the endplates made of $YBa_2Cu_3O_{7-{\delta}}$(YBCO) film on $LaAlO_3$ is measured by using the S-parameter circle-fit method at a frequency of about 19.6 GHz and temperatures of 30 K to 90 K, which is compared with the measured values by using the Lorentzian-fit method. Good agreements are found between the two sets of $Q_0$ values measured by using the two different methods whether the resonator is used in a weak-coupling scheme or a strong-coupling scheme, showing reliability of both methods fur measuring the resonator $Q_0$ accurately. The $Q_0$ of sapphire resonators with a gap between the top plate and the rest of the resonator is also discussed.

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병원급식 종사자의 급식서비스 질 평가 (Evaluation of Foodservice Quality on the Viewpoint of Personnel in Hospital Foodservice)

  • 이해영;장승희;양일선
    • 대한영양사협회학술지
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    • 제10권4호
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    • pp.401-406
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    • 2004
  • The purposes of this study was to evaluate the foodservice quality on the viewpoint of personnel in hospital foodservice. In result, S hospital's foodservice quality, that was evaluated by personnel, was comparatively high on the every variables and factors, especially on 'Q13. Meals delivery to the bed'(4.70 out of 5.0), 'Q14. Removal service of tray by foodservice personnel'(4.63), 'Q15. Kind foodservice personnel'(4.63), 'Q16. Foodservice personnel's clean and neat uniforms'(4.56) and 'factor 4. personnel attitude'(4.63). Foodservice quality factors weren't significant by general characteristics of personnel, thus all personnel were considered to hold similarly the level of foodservice quality. On the basis of these results, the gap between foodservice providers and customers need to be analyzed in the further study.

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RFIC 설계에 응용 가능한 90nm 공정 기반 인덕터의 Quality factor 및 Effective inductance 분석 (Analysis of Quality factor and Effective inductance of Inductor for RF Integrated Circuits in 90nm CMOS Technology)

  • 장성용;신종관;권혁민;권성규;성승용;황선만;장재형;이가원;이희덕
    • 전자공학회논문지
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    • 제50권5호
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    • pp.128-133
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    • 2013
  • 본 논문에서는 RFIC 설계에 응용 가능한 인덕터의 Quality factor 및 Effective inductance를 비교 분석하기 위해 Octagonal 인덕터를 90nm CMOS 공정을 이용하여 제작하였다. 내부반경을 설계변수로 갖는 인덕터의 경우 내부반경이 증가함에 따라 Quality factor가 감소하고 Effective inductance의 값이 증가하였다. 회전수를 설계변수로 갖는 인덕터의 경우 금속의 회전수가 증가함에 따라 Quality factor의 값이 감소하고 Effective inductance의 값이 증가하는 것을 확인하였다. 따라서 RFIC 회로 설계에 있어서 인덕터의 구조는 Q-factor 및 inductance 각각의 상대적 중요도에 따라 선택 되어져야 된다고 할 수 있다.

RFIC를 위한 실리콘 기판에서의 고품질 본드와이어 인덕터 구현 (Implementation of High-Q Bondwire Inductors on Silicon RFIC)

  • 최근영;송병욱;김성진;이해영
    • 대한전자공학회논문지TC
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    • 제39권12호
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    • pp.559-565
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    • 2002
  • 현재 RFIC를 위해 실리콘 기판상에 구현되는 인덕터의 Q 값은 12 이하로 알려져있기 때문에, 고성능 회로설계를 위해서는 더욱 높은 Q 값을 갖는 인덕터의 구현이 필수적이다. 본 논문에서는 본드와이어를 이용하여 높은 Q 값을 가지는 두 개의 인덕터를 제안하였고, 동일한 인덕터에 PGS를 적용하여 총 4가지 형태의 인덕터를 구현하였다. 제안된 본드와이어 인덕터는 일반적인 금속선로보다 넓은 단면적 때문에 상대적으로 작은 도체 손실을 갖고, 인덕터의 상당부분이 공기 중에 위치하므로 기생 캐패시턴스 성분을 줄일 수 있다. 해석 및 측정결과 1.5 GHz 에서 기존의 나선형 인덕터보다 상당히 개선된 15이상의 Q 값을 가짐을 확인하였다. 또한 자동 본딩 머신을 사용하여 구현하기 때문에, 동일한 형태의 인덕터를 반복적으로 쉽게 만들 수 있다.

전자선 선질 R50=1.0과 1.4 g/cm2에 대한 PTW-Markus 전리함의 선질보정인자 결정에 관한 연구 (Determination of Beam Quality Correction Factors for the PTW-Markus Chamber for Electron Beam Qualities R50=1.0 and 1.4 g/cm2)

  • 김미영;이동주;문영민;정동혁
    • 한국의학물리학회지:의학물리
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    • 제26권3호
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    • pp.178-184
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    • 2015
  • 마커스 전리함은 치료용 전자선의 흡수선량 측정에 널리 사용되는 소형 평행 평판형 전리함이다. 특히 TRS-398 프로토콜에서는 $R_{50}<4.0g/cm^2$ (약 10 MeV 이하)에서 평행 평판형 전리함의 사용을 권고하고 있다. 그러나 TRS-398 프로토콜에서 $R_{50}<2.0g/cm^2$ (약 4 MeV 이하)에 대한 선질보정인자($k_{Q,Q_0}$)가 없어 낮은 에너지에 대한 선량측정이 필요한 경우에 마커스 전리함을 사용할 수 없다. 본 연구에서는 몬테칼로 계산(DOSRZnrc/EGSnrc)과 선량학적 계산을 이용하여 전자선 선질 $R_{50}=1.0$, 1.4, 2.0, 2.5, 3.0, $5.0g/cm^2$에 대하여 마커스 전리함(PTW-M34045)에 대한 $k_{Q,Q_0}$를 결정하였다. 본 연구에서는 결정된 $k_{Q,Q_0}$에 대해 TRS-398 및 TG-51 프로토콜의 자료와 알려진 자료들을 이용하여 평가하였다.

고출력 압전 디바이스 응용을 위한 PZ-PT-PMN계 압전 세라믹의 특성 (The Characteristics of PZ-PT PMN Piezoelectric Ceramics for Application to High Power Device)

  • 홍종국;;이종섭;채홍인;윤만순;임기조;정수현
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제49권3호
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    • pp.156-156
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    • 2000
  • The piezoelectric properties and the doping effect for $0.95Pb(Zr_xTi_{l-x})O_3+0.O5Pb(Mn_{1/3}Nb_{2/3})O_3$compositions were studied. Also, the heat generation and the change of electromechanical characteristics, the important problem in practical usage, were investigated under high electric field driving. As a experiment results under low electric field, the value of $k_p$ and ${\varepsilon}_{33}^T$ were maximized, but $Q_m$ was minimized $(k_p=0.57, Q_m=1550)$ in the composition of x=0.51. In order to increase the values of $Q_m$, $Nb_2O_5$ was used as a dopant. As the result of that, the grain size was suppressed and the uniformity of grain was improved. Also, the values of $k_p$ decreased, and the values of $Q_m$ increased with doping concentration of $Nb_2O_5$ . As a experiment results under high electric field driving, when vibration velocity was ower than 0.6[m/s], the temperature increase was 20[℃], and the change ratio of mechanical quality factor was less than 10[%]. So, its electromechanical characteristics was very stable. Conclusively, piezoelectric ceramic composition investigated at this paper is suitable for application to high power piezoelectric devices.

압전 액츄에이터에 활용할 저온소결 압전 세라믹스에 관한 연구 (A Study on the Low Temperature Sintering Piezoelectric Ceramics for Piezoelectric Actuator Application)

  • 류성림;이유형;이상호;류주현
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.277-278
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    • 2007
  • In this study, in order to develop multilayer piezo-actuator, PMN-PNN-PZT ceramics were fabricated using $Li_2CO_3,\;Na_2CO_3$, ZnO as sintering aids and their piezoelectric and dielectric properties were investigated according to the Bi substitution. Bi substitution enhanced electromechanical coupling factor$(k_p)$ and dielectric constant$({\varepsilon}_r)$. However, mechanical quality factor was deteriorated. At the sintering temperature of $870^{\circ}C$ and Bi substitution of 1mol%, density, electromechanical coupling factor$(k_p)$, mechanical quality factor$(Q_m)$, Dielectric constant$({\varepsilon}_r)$ and piezoelectric constant$(d_{33})$ of specimen showed the optimum value of $7.878g/cm^3$, 0.608, 835, 1603 and 397pC/N, respectively.

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여성에 대한 태도분석 (An Attitudinal Study on Women)

  • 여정희
    • 대한간호학회지
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    • 제33권3호
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    • pp.347-355
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    • 2003
  • Purpose: This study was formed to propose a theoretical background for improving the quality of women's lives by measuring the subjectivity on women. Method: Q-methodology is used for purpose. Q-statements are collected through in-depth interviews and a literature review. 34 Q-statements were selected. There are 33 subjects in the research. The Q-Factor Analysis using PC Quanl program was performed to analyze the data. Result: There were three types of opinions on woman. The first type(equal-recognitive) thinks that men and women are equal, women can handle men, and women are independent, valuable beings. The second type(equal-fixed idea) express that women are not behind men in terms of abilities but are supposed to live for the sake of their husbands and children. The third type(equal-practical) answer that men and women are equal, but women have their own personalities and can participate in social activities and can financially help the families. Conclusion: The study express the overall opinions and attitudes on woman as reviewed by the research subjects. Therefore, this study helps the seizure of an opportunity to build a theoretical base for improving the quality of women's lives.

$La_2O_3$ 첨가에 따른 무연 BNKT세라믹의 압전 특성 (Piezoelectric properties of Pb-free BNKT ceramics with the amount of $La_2O_3$ addition)

  • 이현석;이창배;류주현;정영호;홍재일;정광현
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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    • pp.145-149
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    • 2004
  • In this study, leed-free piezoelectric ceramics were investigated for pressure sensor applications as a function of the amount of $La_2O_3$ addition at BNKT system. With increasing amount of $La_2O_3$ addition, density and dielectric constant were increased up to 0.9wt% addition and decreased after 0.9wt% addition, electromechanical coupling factor$(k_p)$ and mechanical quality factor$(Q_m)$ showed the maximum values at 0.2wt% addition and decreased after 0.2wt% addition. The $k_p$, density, dielectric constant and $Q_m$ were showed the optimum values of 0.40, $5.71g/cm^3$, 768 and 118 at $La_2O_3$ 0.2wt% addition, respectively.

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