• 제목/요약/키워드: negative coefficient

검색결과 1,457건 처리시간 0.031초

흰쥐의 체액량과 체중 및 무지방 체중 사이의 관계 (Relation between Various Body Fluid Volumes and Body Weight or Lean Body Mass in the Rats)

  • 안형채;남기용
    • The Korean Journal of Physiology
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    • 제3권1호
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    • pp.1-9
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    • 1969
  • Relationships between red ceil volume $(^{51}Cr-cell)$, total blood volume (red cell volume divided by hematocrit ratio), and extracellular fluid volume (SCN distribution space) and body weight (ranging between 73 and 384 grams) or lean body mass were studied in 59 nembutalized rats. Lean body mass was determined by means of underwater weighing method on rats clipped and eviscerated. There were positive correlations between body weight or lean body mass and the absolute values (in milliliters) of body fluid volumes. Body fluid volumes expressed on the body weight or lean body mass basis, however, showed negative correlations between body weight (grams) or lean body weight (grams) with one exception. Red cell volume expressed as % lean body mass showed a positive correlation with lean body mass. The other results are summarized as follows: 1. Body density of rats was 1.0561 $(range:\;1.0123{\sim}1.0781)$ and 19.8% body weight of total body fat was obtained. The mean value of lean body mass was 80.2% body weight 2. The correlation between body weight and lean body mass was high, namely, coefficient of correlation was r=.99. 3. The correlation between the absolute value of red cell volume (ml) and body weight showed a high correlation, namely, r= 92 and between the lean body mass coefficient of correlation was r=.93. On a weight basis, red cell volume was 2.67 ml/100 gm body weight or 3.48 ml/100 gm lean body mass. The coefficient of correlation between body weight (grams) and red cell volume (% body weight) was r=-. 30. The coefficient of correlation between lean body mass (grams) and red cell volume (% lean body mass) was r=. 50. Thus, the following regression equation was obtained. Red cell volume (% lean body mass)=. 00243 Lean body mass (gm)+3. 12. 4. Total blood volume was 6.06% body weight or 7.83% lean body mass. The correlation between these blood volume values and body weight or lean body mass were negative, namely, r= -.43 and r=-.42 respectively. 5. Extracellular volume (SCN space) was 30.0% body weight or 37.2% lean body mass. These percentage values showed negative correlations between body weight or lean body mass and coefficients of correlation were r=-.40 and r=-.54 respectively. 6. The rate of increase in body weight or lean body mass is accompanied by a smaller rate of increase in blood volume and extracellular fluid volume. The rate of increase in red ceil volume paralled that of lean body mass.

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도시림의 여름 대기온도 저감효과 - 서울시를 대상으로 - (The Effects of Urban Forest on Summer Air Temperature in Seoul, Korea)

  • 조용현;신수영
    • 한국조경학회지
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    • 제30권4호
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    • pp.28-36
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    • 2002
  • The main purpose of this study was to estimate a new regression model to explain the relationship between urban forest and air temperature in summer, 2001. This study consists of two parts: correlation coefficient analysis and regression analysis. According to correlation coefficient analysis, thermal infra-red radiations of the major land use categories found significant difference in each category. However there were no significant relationship between the data (thermal infra-red radiation and NDVI) derived from Landsat-7 ETM+ image and air temperature at Automatic Weather Stations(AWSs). After estimating various regression models for summer air temperature, the final models were chosen. The final regression models consisted of two variables such as forest m and traffic facilities area. The regression models explained over 78% of the variability in air temperatures. The regression models with variables of forest area and traffic facilities area showed that the coefficient of the first variable was even more significant than the second one. However, the negative impact of the traffic facilities area was slightly greater than the positive impact of the forest area. Consequently, the effects of forest area and traffic facilities area were apparent to explain summer air temperature in Seoul. Therefore two policies have the most important implications to mitigate the summer air temperature in Seoul: to expand and to conserve the urban forest; and to change the Oafnc facilities'characteristics. The results from this study are expected to be useful not merely in informing the public that urban forest mitigates summer air temperahne, but in urging the necessity of budgets for trees and managing urban forests. It is recommended that field swey of summer air temperature be Performed for the vadidation of the models. The main purpose of this study was to estimate a new regression model to explain the relationship between urban forest and air temperature in summer, 2001. This study consists of two parts: correlation coefficient analysis and regression analysis. According to correlation coefficient analysis, thermal infra-red radiations of the major land use categories found significant difference in each category. However there were no significant relationship between the data (thermal infra-red radiation and NDVI) derived from Landsat-7 ETM+ image and air temperature at Automatic Weather Stations(AWSs). After estimating various regression models for summer air temperature, the final models were chosen. The final regression models consisted of two variables such as forest m and traffic facilities area. The regression models explained over 78% of the variability in air temperatures. The regression models with variables of forest area and traffic facilities area showed that the coefficient of the first variable was even more significant than the second one. However, the negative impact of the traffic facilities area was slightly greater than the positive impact of the forest area. Consequently, the effects of forest area and traffic facilities area were apparent to explain summer air temperature in Seoul. Therefore two policies have the most important implications to mitigate the summer air temperature in Seoul: to expand and to conserve the urban forest; and to change the traffic facilities'characteristics. The results from this study are expected to be useful not merely in informing the public that urban forest mitigates summer air temperature, but in urging the necessity of budgets for trees and managing urban forests. It is recommended that field survey of summer air temperature be Performed for the vadidation of the models.

Matrix-Assisted Variable Wavelength Laser Desorption Ionization of Peptides; Influence of the Matrix Absorption Coefficient on Expansion Cooling

  • Ahn, Sung-Hee;Bae, Yong-Jin;Kim, Myung-Soo
    • Bulletin of the Korean Chemical Society
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    • 제33권9호
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    • pp.2955-2960
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    • 2012
  • Product ion yields in the in- and post-source decays of three peptide ions, $[Y_5X+H]^+$ (X = Y (tyrosine), K (lysine), and R (arginine)), generated by matrix-assisted laser desorption ionization (MALDI) were measured at six wavelengths, 307, 317, 327, 337, 347, and 357 nm, using ${\alpha}$-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB) as the matrices. The temperatures of the early and late plumes generated by MALDI were estimated via kinetic analysis of the product ion yield data. For both matrices, the temperature drop (${\Delta}T$), i.e. the difference in the temperature between the early and late plumes, displayed negative correlation with the absorption coefficient. This was in agreement with the previous reasoning that deeper laser penetration and larger amount of material ablation arising from smaller absorption coefficient would result in larger extent of expansion cooling. The results support the postulation of the expansion cooling occurring in the plume presented previously.

기모직물의 가공공정 및 기모횟수가 역학적 특성치에 미치는 영향(II) -드레이프성 및 방추성을 중심으로- (Effects of Treatment Process and Brushing Condition on Mechanical Properties of Brushed Fabrics (II) -Drapability and Wrinkle Recovery of Brushed Fabrics-)

  • 권헌선;권오경;성수광
    • 한국의류학회지
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    • 제18권5호
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    • pp.595-601
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    • 1994
  • This study was accomplished to investigate drape coefficient and wrinkle recovery of brushed fabrics according to treatment processes and brushing conditions. For this study, grey fabrics of blended ratio of polyester 65% : cotton 35% were bleached and dyed. These fabrics were then brushed 1, 3, 5 and 7 times. Drape coefficient and wrinkle recovery of brushed fabrics were measured by drape tester and shirley crease recovery tester respectively. The experimental results were analysed statistically to relate mechanical properties, handle, drapability, and wrinkle recovery 1) Drape coefficients of dyed fabric showed lower values and wrinkle recovery showed higher ones than those of bleached and dyed fabrics. Especially dyed fabric brushed 3 times showed good appearance and form stability. 2) Considering the blocked properties that contribute to the drape coefficient and wrinkle recovery of brushed fabrics, bending and shearing properties had a high degree of correlation with brushed fabrics, and 2HB/W showed a high positive correlation with drape coefficient and a high negative correlation with wrinkle recovery.

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더미스터 온도센서를 이용한 나노유체의 대류열전달계수 측정 장치 (Measuring Apparatus for Convective Heat Transfer Coefficient of Nanofluids Using a Thermistor Temperature Sensor)

  • 이신표
    • 대한기계학회논문집B
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    • 제40권2호
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    • pp.103-110
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    • 2016
  • 나노유체의 대류열전달 성능을 평가하는 센서로서 가는 백금 열선이 많이 사용되었다. 그러나 센서의 강도가 약해서 취급에 주의가 필요하고 측정실험에서 센서에 대한 엄밀한 교정과정을 생략하거나 정밀도 높은 기구들을 사용하지 않으면 비현실적인 대류열전달계수가 얻어졌다. 본 연구에서는 백금 열선 대신 더미스터 센서를 채택한 새로운 나노유체 대류 성능 평가장치를 제안하였고 그 작동 원리를 자세히 설명하였다. 순수 엔진오일에 대한 두 센서의 비교 실험을 통하여 더미스터 센서의 실용적 장점을 확인할 수 있었다. 제안된 장치는 개발된 나노유체의 채택 여부를 판단하는 유용한 도구로 사용될 수 있을 것이다.

접촉 강성을 고려한 디스크브레이크의 면외진동 해석 (Analysis of Out-of-plane Motion of a Disc Brake System Considering Contact Stiffness)

  • Joe, Yong-Goo;Oh, Jae-Eung;Shin, Ki-Hong
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.597-600
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    • 2004
  • A two-degree-of-freedom out-of-plane model with contact stiffness is presented to describe dynamical interaction between the pad and disc of a disc brake system. It is assumed that the out-of-plane motion of the system depends on the friction force acting along the in-plane direction. Dynamic friction coefficient is modelled as a function of both in-plane relative velocity and out-of-plane normal force. When the friction coefficient depends only on the relative velocity, the contact stiffness has the role of negative stiffness. The results of stability analysis show that the stiffness of both pad and disc are equally important. Complex eigenvalue analysis is conducted for the case that the friction coefficient is also dependent on the normal force. The results further verify the importance of the stiffness. It has also been found that increasing the gradient of friction coefficient with respect to the normal force makes the system more unstable. Nonlinear analysis is also performed to demonstrate various responses. Comparing the responses with experimental data has shown that the proposed model may qualitatively well represent a certain type of brake noise.

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The Board Size and Board Composition Impact on Financial Performance: An Evidence from the Pakistani and Chinese's Listed Banking Sector

  • MAJEED, Muhammad Kashif;JUN, Ji Cheng;ZIA-UR-REHMAN, Muhammad;MOHSIN, Muhammad;RAFIQ, Muhammad Zeeshan
    • The Journal of Asian Finance, Economics and Business
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    • 제7권4호
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    • pp.81-95
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    • 2020
  • The main objective of this research is to investigate the impact of board size and board composition on financial performance of banks. The sample of this study consists on two countries listed bank sector Pakistan and China. The annul data is used from 2009-2018 to find the objective of this study. The Panel regression model is used to check the relationship between dependent and independent variables. Return on Asset and Return on Equity is used as performance checker dependent variables. The results of this study confirm board size coefficient value positive for ROA and negative for ROE but shows insignificant behavior for Pakistani banking sector while in Chinese banking sector the coefficient value of board size positively for ROA and ROE at 10% level. The board composition coefficient shows the negatively significant with ROA but insignificantly related to ROE for Pakistani banking sector. However, in Chinese banking sector the coefficient value of board composition is insignificant for both ROA and ROE. This study is helpful for banks, management of banks, policy makers, researcher as well as Government.

Asian Stock Markets Analysis: The New Evidence from Time-Varying Coefficient Autoregressive Model

  • HONGSAKULVASU, Napon;LIAMMUKDA, Asama
    • The Journal of Asian Finance, Economics and Business
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    • 제7권9호
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    • pp.95-104
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    • 2020
  • In financial economics studies, the autoregressive model has been a workhorse for a long time. However, the model has a fixed value on every parameter and requires the stationarity assumptions. Time-varying coefficient autoregressive model that we use in this paper offers some desirable benefits over the traditional model such as the parameters are allowed to be varied over-time and can be applies to non-stationary financial data. This paper provides the Monte Carlo simulation studies which show that the model can capture the dynamic movement of parameters very well, even though, there are some sudden changes or jumps. For the daily data from January 1, 2015 to February 12, 2020, our paper provides the empirical studies that Thailand, Taiwan and Tokyo Stock market Index can be explained very well by the time-varying coefficient autoregressive model with lag order one while South Korea's stock index can be explained by the model with lag order three. We show that the model can unveil the non-linear shape of the estimated mean. We employ GJR-GARCH in the condition variance equation and found the evidences that the negative shocks have more impact on market's volatility than the positive shock in the case of South Korea and Tokyo.

Notchback자동차의 트렁크 높이와 공기속도가 차체 표면의 압력변화에 미치는 영향 (Effect of Trunk Height and Approaching Air Velocity of Notchback Road Vehicles on the Pressure Distribution of the Car Surface)

  • 박종수;최병대;김성준
    • 한국자동차공학회논문집
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    • 제10권6호
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    • pp.178-186
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    • 2002
  • 3-D numerical studies are performed to investigate the effect of the trunk height and approaching air velocities on the pressure distribution of notchback road vehicle. For this purpose, the models of test vehicle with four different trunk heights are introduced and PHOENICS, a commercial CFD code, is used to simulate the flow phenomena and to estimate the values of pressure coefficients along the surface of vehicle. The standard k-$\xi$ model is adopted for the simulation of turbulence. The numerical results say that the height variation of trunk makes almost no influence on the distribution of the value of pressure coefficient along upper surface but makes very strong effects on the rear surface. That is, the value of pressure coefficient becomes smaller as the height is increased along the rear surface and the bottom surface. Approaching air velocity make no differences on pressure coefficients. Through the analysis of pressure coefficient on the vehicle surfaces one tried to assess aerodynamic drag and lift of vehicle. The pressure distribution on the rear surface affected more on drag and lift than pressure distribution on the front surface of the vehicle does. The increase of trunk height makes positive effects on the lift decrease but negative effects on drag reduction.

반응표면분석법에 의한 적층 칩 바리스터의 전기적 특성 (Electrical Properties of Multilayer Chip Varistors in the Response Surface Analysis)

  • 윤중락;정태석;최근묵;이석원
    • 한국전기전자재료학회논문지
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    • 제20권6호
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    • pp.496-501
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    • 2007
  • In order to enhance sintering characteristics on the $ZnO-Pr_6O_{11}$ based multilayer chip varistors (MLVs), a response surface analysis using central composite design method were carried out. As a result, varistor voltage($V_{1mA}$), nonlinear coefficient ($\alpha$), leakage current ($I_L$) and capacitance (C) were considered to be mainly affected by sintered temperature and holding time. MLVs sintered at $1200^{\circ}C$ and above $1200^{\circ}C$ revealed poor electrical characteristics, possibly due to the reaction between electrode materials(Pd) and $ZnO-Pr_6O_{11}$ based ceramics. On the sintering temperature range $1150{\sim}1175^{\circ}C$, nonlinear coefficient ($\alpha$) and leakage current ($I_L$) were shown to be $60{\sim}69$ and below $0.3{\mu}A$, respectively. In particular, MLVs sintered at $1175^{\circ}C$, 1.5 hr and $2^{\circ}C/hr$ (cooling speed) showed stable ESD(Electrical Static Discharge) characteristics under the condition of 10 times at 8 Kv with deviation varistor voltage, and deviation nonlinear coefficient were 0.3% and 0.33% (at positive), 0.55% (at negative), respectively.