• 제목/요약/키워드: quality coefficient

검색결과 2,436건 처리시간 0.04초

($Ba_{1-x}Sr_{x}$)O-$Sm_2O_3$-$TiO_2$세라믹스의 마이크로파 유전특성 (Microwave Dielectric Properties of the ($Ba_{1-x}Sr_{x}$)O-$Sm_2O_3$-$TiO_2$ Ceramics.)

  • 박인길;류기원;배선기;이영희
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1995년도 추계학술대회 논문집
    • /
    • pp.5.2-8
    • /
    • 1995
  • 0.15($Ba_{1-x}Sr_{x}$)O-$0.15Sm_2O_3$-$0.7TiO_2$(x=0∼9[m/o]ceramics were fabricated by mixed-oxide method. Microwave dielectric properties were investigated with sintering conditions aid Sr addictive. In the specimen with x=0[m/o] sintered at 1350∼1470[$^{\circ}C$], dielectric constant, quality factor and temperature coefficient of resonant frequency were 70∼74, 2800∼3300(at 3[GHz]), -1.33∼+l.66[ppm/$^{\circ}C$, respectively. Increasing the Sr additive from 0 to 5[m/o], dielectric constant and temperature coefficient of resonant frequency were increased and quality factor was decreased. In the specimen with x=r[m/o] sintered at 1375[$^{\circ}C$], 6[hr], dielectric constant, quality factor and temperature coefficient resonant frequency were 75.62, 2785(at 3[GHz]), +8.39[ppm/$^{\circ}C$], respectively.

BSST계 세라믹스의 마이크로파 유전특성에 미치는 $Nd_2O_3$ 첨가 효과 (The effect of $Nd_2O_3$ addition on the microwave dielectric properties of the BSST ceramics)

  • 박인길;류기원;배선기;이영희
    • E2M - 전기 전자와 첨단 소재
    • /
    • 제9권5호
    • /
    • pp.439-444
    • /
    • 1996
  • 0.15(B $a_{0.95}$ S $r_{0.05}$)O-0.15(S $m_{2(1-x}$/N $d_{2x}$) $O_{3}$-0.7Ti $O_{2}$(x=0-10[m/o]) ceramics were fabricated by mixed oxide method. Microwave dielectric properties were investigated with contents of N $d_{2}$ $O_{3}$. In the case of specimen with N $d_{2}$ $O_{3}$(6[m/o]), dielectric constant, quality factor and temperature coefficient of resonant frequency were 78.14, 2938(at 3[GHz]) and +14.19[ppm/.deg. C], respectively. By comparison its properties with undoped specimen, dielectric constant and quality factor were highly improved, but the temperature coefficient of resonant frequency was increased to positive value......

  • PDF

0.15(B $a_0.95$S $r_ 0.05$)O-0.15S $m_2$ $O_3$-0.7TiO $_2$ 세라믹스의 마이크로파 유전특성 (Microwave dielectric properties of the 0.15(B $a_0.95$S $r_ 0.05$)O-0.15S $m_2$ $O_3$-0.7TiO $_2$ ceramics)

  • 박인길;정장호;배선기;이영희
    • E2M - 전기 전자와 첨단 소재
    • /
    • 제8권2호
    • /
    • pp.224-228
    • /
    • 1995
  • 0.15(B $a_{0.95}$ S $r_{0.05}$)O-0.15S $m_{2}$ $O_{3}$-0.7Ti $O_{2}$ ceramics were fabricated by the mixed-oxide method. Microwave dielectric properties were investigated with sintering conditions. Increasing the sintering temperature from 1300 to 1375[.deg. C], the sintered density was increased from 5.44 to 5.63[g/c $m^{3$]. Increasing the sintering temperature, dielectric constant and quality factor were increased and temperature coefficient of resonant frequency was independent of sintering temperature. In the specimen sintered at 1375[.deg. C], dielectric constant, quality factor and temperature coefficient of resonant frequency were 80.79, 2784(at 3[GHz]), +11.07[ppm/.deg. C], respectively..

  • PDF

외식기업의 레스토랑 환경과 혼잡지각에 관한 연구 (A Study on Restaurant Envirionment and Crowding in Foodservice Company)

  • 양태석
    • 한국조리학회:학술대회논문집
    • /
    • 한국조리학회 2006년도 제41차 정기하계학술세미나
    • /
    • pp.115-134
    • /
    • 2006
  • This study was conducted during a period from July 4 to 30 to investigate the effect of restaurant environment upon customer's satisfaction and crowdedness awareness. Total 800sets of questionnaire were distributed among major food service corporations. They were 16 restaurants from McDonald, Burger King, Popeyes, KFC, Rits Carlton, Intercontinental, The Westin Chosun, Hilton, Merriot, Outback Steak House, Bennigans, VIPS, Pizza Hut Pul-hyanggi(Scent of grass), Nolboo Co.,, and Our Story, and received 50 see each to hand out to their customers. Out of total 800 sets of questionnaires, 592 sets (74.25% were retrieved and underwent a Multiple Regression Analysis. We found the following results from the study. First among each variable of restaurant environment that had a significant effect on the crowding, 'pTast service' and 'responsiveness to customer complaints' sooted a regression coefficient value 0.381 and 0.325 respectively. Second, among each restaurant environment factor that had a significant effect on crowding, 'quality of facility' sooted the highest regression coefficient value 0.423 with a standard error score 0.1074, fellowed by 'status of waiting', 'overall ambience' and 'service quality' in ascending order. Third, in the analysis of the effect of each environmental factor upon the satisfaction rate, 'status of waiting' showed the highest regression coefficient value 0.3821 with a standard error score 0.4565, followed by 'cleanliness', 'service quality' and 'conveniency', in ascending order.

  • PDF

외식기업의 레스토랑 환경과 혼잡 지각에 관한 연구 (A Study on Restaurant Environment and Crowdedness in Foodservice Company)

  • 박영배;양태석
    • 한국조리학회지
    • /
    • 제12권4호
    • /
    • pp.63-79
    • /
    • 2006
  • This study was conducted to investigate the effect of restaurant environment upon customers' satisfaction and crowdedness awareness from July 4 to 30. Total 800 sets of questionnaire were distributed among major foodservice corporations including 16 restaurants from McDonald, Burger King, Popeyes, KFC, Ritz Carlton, Intercontinental, The Westin Chosun, Hilton, Merriot, Outback Steak House, Bennigans, VIPS, Pizza Hut, Pul-hyanggi(Scent of grass), Nolboo Co., and Our Story. They received 50 sets each to hand out to their customers. Out of total 800 sets of questionnaires, 592 sets (74.25%) were retrieved and underwent the Multiple Regression Analysis. We found the following results from the study. First, among each variable of restaurant environment that had a significant effect on crowdedness, "fast service" and "responsiveness to customer complaints" scored a regression coefficient value 0.381 and 0.325 respectively. Second, among each restaurant environment factor that had a significant effect on crowdedness, "quality of facilities" scored the highest regression coefficient value 0.423 with a standard error score 0.1074, followed by "condition of waiting", "overall ambience" and "service quality" in ascending order. Third, in the analysis of the effect of each environmental factor upon the satisfaction rate, "condition of waiting" showed the highest regression coefficient value 0.3821 with a standard error score 0.4565, followed by "cleanliness", "service quality" and "convenience', in ascending order.

  • PDF

내부통제와 미래이익에 대한 주가 정보성 (Internal Control and Stock Price Informativeness about Future Earnings)

  • 왕람;박희우
    • 아태비즈니스연구
    • /
    • 제14권4호
    • /
    • pp.255-273
    • /
    • 2023
  • Purpose - This study examines whether internal control has an effect on stock price informativeness about future earnings. High quality internal control provides continuous assurance for the quality of financial reports, and these future earnings-related information is accurately reflected in the current stock price. Design/methodology/approach - This study collected 12,862 data from 2006 to 2021 in China to make an empirical analysis using the future earnings response coefficient (FERC) and the multiple regression analysis were hired in order to analyze the data. Findings - We find that internal control strengthens the association between current returns and future earnings, indicating that more information about future earnings is reflected in current stock prices. This positive effect exists in both the main board market and the growth enterprise market of China's stock market, especially in the main board market after the implementation of the internal control policy. In addition, we find that the positive effect is weaker for firms that report internal control deficiencies or receives non unqualified internal control audit opinions. The results using earnings persistence yield similar findings, further supporting the results based on the FERC model. Research Implications or Originality - Our tests provide strong evidence that the quality of internal control affects FERC in China stock market.

수질모의시 적정 탈산소계수 선정을 위한 연구 - 황구지천을 대상으로 - (A study on rationalized values of deoxygenation coefficient for stream quality modelling in the Hwangguji stream)

  • 노희성;안태진
    • 한국습지학회지
    • /
    • 제21권1호
    • /
    • pp.77-83
    • /
    • 2019
  • 2002년 및 2014년 수행된 황구지천 하천기본계획 수립에 있어서 수질오염농도의 예측을 수행하였지만, 수질 예측모델링 과정에서 관행적으로 적용한 반응계수를 적용함으로써 수질 예측 결과의 신뢰도가 낮은 것으로 평가되고 있다. 본 연구에서는 황구지천 국가하천 약 7.8 km 본류구간인 세마교와 수직교사이에서의 탈산소계수를 평가하여 기존 수질모델링에서 적용한 탈산소계수와 비교하고자 하였다. 관측자료를 통하여 황구지천 세마교 지점(HGJ2)부터 수직교 지점(HGJ3)구간에서 풍수 기간일 경우 탈산소계수는 $0.078day^{-1}{\sim}0.748day^{-1}$, 갈수 기간일 경우는 $0.053day^{-1}{\sim}0.505day^{-1}$ 등으로 산정되었다. 2002년에 수행된 황구지천 수질 예측모델링에서 적용한 탈산소계수는 $0.02day^{-1}{\sim}3.4day^{-1}$ 범위의 값을 적용하였으며, 2014년에는 $0.043day^{-1}$을 적용하였다. 따라서 2002년에는 실제 관측된 수질보다 긍정적으로 예측되었으나, 2014년에는 실제 관측 수질보다 부정적으로 예측되었다. 이는 여러 요인이 있겠지만 적정한 탈산소계수의 적용도 상당한 요인이 작용한 것으로 보이며, 향후 수질예측모델링에서 관측자료가 있는 경우에는 관측자료에 의한 탈산소계수의 결정을 통하여 수행할 필요가 있다고 판단된다.

낙동강유역 장기 수질모니터링을 통한 계절적 특성분석 연구 (A study on seasonal characteristics through long-term water quality monitoring in the Nakdong River Watershed)

  • 갈병석;박재범;김성민;신상민;장순자;전민재
    • 한국습지학회지
    • /
    • 제24권4호
    • /
    • pp.301-311
    • /
    • 2022
  • 본 연구는 장기 수질모니터링 자료를 이용하여 수질의 계절적 특성을 분석하는 것이 목적이다. 낙동강수계에서 장기 모니터링이 수행되고 있는 34개 지류에서의 모니터링 자료를 이용하여 수질의 계절적 특성을 분석하였고 계절적 분석을 위해 수질의 평균 자료 분석과 변동계수(Coefficient of variation) 분석, 추세분석을 수행하였다. 변동계수 평가결과, 지류가 본류보다 크고 계절적으로는 BOD와 T-P, TOC는 가을철이 크고 T-N은 봄철이 크게 나타났다. 추세분석은 Mann-Kendall과 Sen's Slope를 통해 분석하였으며 BOD와 T-N, T-P는 감소 경향이 많으나 TOC는 증가 경향이 많았다. 또한, 공간적으로는 낙동강 상류보다 하류에서의 증가하는 경향이 많이 나타났다. 본 연구를 통해 장기 수질모니터링 자료의 활용성 평가 및 계절적 특성을 분석할 수 있었고 유역관리를 위해 수질의 안정화 시기, 오염원 증감 변화를 분석할 수 있었다.

알루미늄 다채널 평판관내 R-22 응축에 관한 연구 (R-22 Condensation in Flat Aluminum Multi-Channel Tubes)

  • 김정오;조진표;김내현
    • 대한기계학회논문집B
    • /
    • 제24권2호
    • /
    • pp.241-250
    • /
    • 2000
  • In this study, condensation heat transfer tests were conducted in flat aluminum multi-channel tubes using R-22. Two internal geometries were tested ; one with smooth inner surface and the other with micro-fins. Data are presented for the followin~ range of variables ; vapor quality($0.1{\sim}0.9$), mass flux($200{\sim}600kg/m^2s$) and heat flux($5{\sim}15kW/m^2$). The micro-fin tube showed higher heat transfer coefficients compared with those of the smooth tube. The difference increased as the vapor quality increased. Surface tension force acting on the micro-fin surface at the high vapor quality is believed to be responsible. Different from the trends of the smooth tube, where the heat transfer coefficient increased as the mass flux increased, the heat transfer coefficient of the micro-fin tube was independent of the mass flux at high vapor quality, which implies that the surface tension effect on the fin overwhelms the vapor shear effect at the high vapor quality. Present data(except those at low mass flux and high quality) were well correlated by equivalent Reynolds number, Existing correlations overpredicted the present data at high mass flux.

노인요양시설 서비스 질 평가 도구 개발 (Development of an Evaluation Instrument for Service Quality in Nursing Homes)

  • 이지아;지은선
    • 대한간호학회지
    • /
    • 제41권4호
    • /
    • pp.510-519
    • /
    • 2011
  • Purpose: The purposes of this study were to identify the factors influencing service quality in nursing homes, and to develop an evaluation instrument for service quality. Methods: A three-phase process was employed for the study. 1) The important factors to evaluate the service quality in nursing homes were identified through a literature review, panel discussion and focus group interview, 2) the evaluation instrument was developed, and 3) validity and reliability of the study instrument were tested by factor analysis, Pearson correlation coefficient, Cronbach's ${\alpha}$ and Cohen's Kappa. Results: Factor analysis showed that the factors influencing service quality in nursing homes were healthcare, diet/assistance, therapy, environment and staff. To improve objectivity of the instrument, quantitative as well as qualitative evaluation approaches were adopted. The study instrument was developed with 30 items and showed acceptable construct validity. The criterion-related validity was a Pearson correlation coefficient of .85 in 151 care facilities. The internal consistency was Cronbach's ${\alpha}$=.95. Conclusion: The instrument has acceptable validity and a high degree of reliability. Staff in nursing homes can continuously improve and manage their services using the results of the evaluation instrument.