• Title/Summary/Keyword: Constant correlation factors

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Constant Correlation Factors between Temkin and Langmuir or Frumkin Adsorption Isotherms at Poly-Pt, Re, and Ni/Aqueous Electrolyte Interfaces

  • Chun Jang H.;Jeon Sang K.;Chun Jin Y.
    • Journal of the Korean Electrochemical Society
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    • v.7 no.4
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    • pp.194-200
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    • 2004
  • The constant correlation factors between the Temkin and the Langmuir or the Frumkin adsorption isotherms of over-potentially deposited hydrogen (OPD H) for the cathodic H2 evolution reaction (HER) at poly-Pt and Re/0.5M $H_2SO_4$ and poly-Ni/0.05 M KOH aqueous electrolyte interfaces have been experimentally and consistently found using the phase-shift method. At intermediate values of the fractional surface coverage $(\theta),\;i.e.,\;02<{\theta}<0.8$, the Langmuir and Temkin adsorption isotherms of OPD H for the cathodic HER are correlated to each other even though the adsorption conditions or processes are different from each other. At the same range of $\theta$, correspondingly, the Frumkin and Temkin adsorption isotherms of OPD H for the cathodic HER are correlated to each other. The equilibrium constants $(K_o)$ for the Temkin adsorption isotherms $({\theta}\;vs.\; E)$ are consistently ca. 10 times greater than those (K, Ko) for the corresponding Langmuir or Frumkin adsorption isotherms ($({\theta}\;vs.\; E)$. The interaction parameters (g) for the Temkin adsorption isotherms $({\theta}\;vs.\; E)$ are consistently ra. 4.6 greater than those (g) for the corresponding Langmuir or Frumkin adsorption isotherms $({\theta}\;vs.\; E)$. These numbers (10 times and 4.6) can be taken as constant correlation factors between the corresponding adsolftion isotherms (Temkin, Langmuir, Frumkin) at the interfaces. The Temkin adsorption isotherm corresponding to the Langmuir or the Frumkin adsorption isotherm, and vice versa, can be effectively verified or confirmed using the constant correlation factors. Both the phase-shift methodand constant correlation factors are useful and effective for determining or confirming the suitable adsorption isotherms (Temkin, Langmuir, Frumkin) of intermediates for sequential reactions in electrochemical systems.

DEVELOPMENT OF A SOUND QUALITY INDEX FOR THE EVALUATION OF BOOMING NOISE OF A PASSENGER CAR BASED ON REGRESSIVE CORRELATION

  • LEE J. K.;PARK Y. W.;CHAI J. B.;JANG H. K.
    • International Journal of Automotive Technology
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    • v.6 no.4
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    • pp.367-374
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    • 2005
  • This paper proposes a sound quality index to evaluate the vehicle interior noise. The index was developed using a correlation analysis of an objective measurement and a subjective evaluation data. First, the objective set of measurements was obtained at two specified driving conditions. One is from a wide-open test condition and the other is from a constant-speed test condition. At the same time, subjective evaluation was carried out using a score of ten scale where 17 test engineers participated in the experiment. The correlation analysis between the psycho-acoustic parameters derived from the objective measurement and the subjective evaluation was performed. The most critical factors at both test conditions were determined, and the corresponding equations for the sound quality were obtained from the multiple factor regression method. Finally, a comparative work between previous index and present index was performed to validate the effectiveness of the proposed index.

Default Bayesian testing for the bivariate normal correlation coefficient

  • Kang, Sang-Gil;Kim, Dal-Ho;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.5
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    • pp.1007-1016
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    • 2011
  • This article deals with the problem of testing for the correlation coefficient in the bivariate normal distribution. We propose Bayesian hypothesis testing procedures for the bivariate normal correlation coefficient under the noninformative prior. The noninformative priors are usually improper which yields a calibration problem that makes the Bayes factor to be defined up to a multiplicative constant. So we propose the default Bayesian hypothesis testing procedures based on the fractional Bayes factor and the intrinsic Bayes factors under the reference priors. A simulation study and an example are provided.

A Study on the Correlation of Organic Factors in Municipal Waste Water (도시하수중 유기인자의 상호기관에 관한 연구)

  • 황상용;손종열;우완기
    • Journal of Environmental Health Sciences
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    • v.16 no.2
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    • pp.55-61
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    • 1990
  • Laboratory methods commonly used today are biochemical oxygen demand, chemical oxygen demand, and total organic carbon. Establishment of constant relationships among the various measures of organic content depends primarily on the nature of the wastewater and its source. Of all the measures, the most difficult to correlate to the others is the BODs test, because of the problems associated with biological tests. The results were summarized as follwos, 1. For typical municipal wastes, however, the SBOD$_{5}$/SCOD$_{cr}$ ratio varies from 0.14 to 0.34(mean 0.21), SBOD$_{5}$/STOC ratio varies from 0.35 to 1.19(mean 0.69) 2. Correlation analysis between the SBOD$_{5}$ and SCOD$_{cr}$ gave good correlation coefficient r = 0.903 and the equation Y = 3.756X + 16,221 was obtained. 3. The correlation between the SBOD$_{5}$ and STOC was well presented with equation : Y = 1,070X + 7,637, and also correlation coefficient r = 0.821 4. The correlation between the SCOD$_{cr}$ and STOC was well presented with equation : Y = 0.256X +5.513 and also correlation coefficient r = 0.816. 5. Because of the rapidity with which the TOC test can be conducted, it is anticipated that more use will be made of these tests in the future.

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Failure Zone Estimation from the correlation between the Temperature in Slope and the Soil Nail Strain (지중온도와 변형율과의 상관관계를 통한 활동영역의 추정)

  • Chang, Ki-Tae
    • Journal of the Korean Geophysical Society
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    • v.8 no.3
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    • pp.123-130
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    • 2005
  • It is necessary, in the light of the importance of long-term slope stability problem, to develop a simple method or tool which can figure out the possible failure zone resulted from weathering effect and other factors. The FBG sensor system is used to estimate the correlations between the temperature and the slope in Kimhae, and to find a failure zone in slopes effectively. This research is to seek for the correlation between the soil temperature distribution and the strain distribution in a active zone by analyzing the data from the in-situ measurement so that the possible failure zone should be well defined based on the correlation. For instance, the zone of high temperature fluctuation can be regarded as one of the possible sliding zone due to the weathering effect while the constant temperature depth of the ground, if exists would not be relatively affected by the weathering process.

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Analysis on Relations between Travel time and Watershed Characteristics (유역특성(流域特性)과 홍수도달시간(洪水到達時間)과의 상관해석(相關解析))

  • Suh, Seung Duk;Lim, Kyu Dong
    • Current Research on Agriculture and Life Sciences
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    • v.5
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    • pp.158-167
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    • 1987
  • The purpose of this study is to inquire and analyse the relation between traveltime (Tc) and watetshed physical characteristics surveyed such as river length (L), Lea, river main slope (s), base length of time area diagram, and storage constant (k). The results obtained in this study are as follows. The average widths of watersheds were with the range from 4.6 kilometers to 16.7 kilometers. The shape factors of main stream ranged from 0.08 to 0.37. The average slopes to main 8tream were within the range of 1.7-5.5 meter per kilometer. The relation between the base length and traveltime from S. C. S. method, Rational method, and RZIHA+KRAVEN method were derived $Tc=0.524{\times}1.35^c$ (r=0.98), $Tc=0.628{\times}1.339^c$, (r=0.98), $Tc=0.667{\times}1.342^c$ (r=0.97). The base length of the time-area diagram (c) for the IUH was derived as $c=0.9(\frac{L.L_{ca}}{\sqrt{s}})^{0.35}$ and correlation coefficient was 0.98 which defined a high significance. The storage constant K, derived in this study was $K=8.32+0.0213{\frac{L}{\sqrt{s}}}$ with correlation coefficient (0.96). The relation between storage Constant and conventional formula were figured out $Tc=0.0003{\times}3.323^k$ (r=0.97). $Tc=0.00045{\times}3.268^k$ (r=0.99) and $Tc=0.0004{\times}3.26^k$ (r=0.963). The base length (c) and storage constant (k) of time-Area Diagram were very important parts that determined traveltime for flood events. In the estimate of travel time for predicting flood volume, the formula of $Tc=0.524{\times}1.35^c$ that would be available to apply the Nak - Dong river watershed area and homogeneous watershed characteristics was found.

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Effect of Curing Conditions on the Characteristics of Chloride Ion Diffusion in Concrete (콘크리트의 염소이온 확산특성에 미치는 양생조건의 영향)

  • 임병탁;배수호;정영수;심은철;하재담
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.715-720
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    • 2003
  • The chief factors for the penetration and diffusion of chloride ions in concrete are water-cement ratio(W/C), aging, curing conditions, chloride ions concentration of given environment., wet and dry conditions and etc. In this study, of these factors effect of curing conditions such as standard and outdoor curing on the characteristics of chloride ions diffusion in concrete were researched when environmental factors for the penetration and diffusion of chloride ions were constant. For this purpose, the voltages passing through the diffusion cell were measured by using accelerated test method using potential difference, and then diffusion coefficients of chloride ions by using Andrade's method were estimated for 44%, 49.5% and 60% of w/c, respectively. As a result., according to curing conditions correlation among diffusion coefficients of chloride ions, W/C and aging were concluded through multiple regression model.

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Factors Influencing Organizational Commitment and Job Satisfaction of Nurses (간호사의 직무만족과 조직몰입에 영향을 미치는 요인)

  • An, Hye-Gyung;Kang, In-Soon
    • Journal of Korean Academy of Nursing Administration
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    • v.12 no.4
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    • pp.604-614
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    • 2006
  • Purpose: This study was to identify factors that influence the organizational commitment and job satisfaction of nurses. Method: The data were collected from 1st, August until 7th, August, 2005. The subjects were 238 nurses from a general hospital in Busan. Data were analyzed with descriptive statistics, t-test, one-way ANOVA, Pearson correlation coefficient, and stepwise multiple regression using SPSS program. Result: The organizational commitment and job satisfaction was significant positive correlations with flexibility, satisfaction, competence factors and significant negative correlations with empathy factors and centralization factor. The most powerful predictors of Nurses's organizational commitment and job satisfaction was managerial strategy of organizational characteristics. And, satisfaction factors of professional self-concept, affiliative-dominant culture and conservative- dominant culture and innovative-dominant culture were powerful predictor factors. The Other powerful predictors of nurses's job satisfaction were satisfaction factors of professional Self-concept, communication and centralization factor of organizational characteristics, affiliative-dominant culture and conservative-dominant culture, professional image factor of nurse image. Conclusion: This study revealed that important factors for nurses's organizational commitment and job satisfaction. Consequently, the manager should be make effective managerial strategy and encourage that nurse have more satisfy to professional self-concept. And the manager make constant efforts to create an affiliative culture in hospital.

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Analysis of asymmetric flow in annulus with square ribs by linearly- varying shear stress model (線型 亂流剪斷應力모델에 의한 直四角形 조도를 갖는 二重圓管內의 非對稱流動의 解析)

  • 이병곤;최영돈
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.11 no.1
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    • pp.88-96
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    • 1987
  • A method is presented to calculate the fiction factor and velocity distribution of asymmetric flow in rough channels and annuli. This method is derived from an assumption of linearly-varying shear stress which is different from Maubach's constant shear stress assumption. This method gives continuous velocity gradient at the position of maximum velocity and the predicted velocity profiles are in better agreements with experimental data than those obtained by Maubach's method. In this paper, a new correlation of roughness function is proposed and the predictions of friction factors by this correlation agree well with experimental data.

Effects of IACC and its Variation on Annoyance of Heavy-weight Floor Impact Sounds (중량충격음 어노이언스 반응에 대한 IACC 변화의 영향)

  • Kumar P. Senthil;Sato, Shin-ichi;Jeon Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.626-630
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    • 2006
  • This study investigates the effects of Interaural Cross-correlation(IACC) and its variation on annoyance of the heavy-weight impact sounds. Subjects evaluated the annoyance of the heavy-weight floor impact sounds recorded in rooms of apartments which have different sound insulation treatments; furnished and occupied conditions are characterized by the ACF/IACF factors. A paired comparison test was conducted using the impact sound sources whose IACC and variation of IACC values were different. It was found that IACC is inversely correlated with the scale value(r=-0.62) whereas the variation of IACC is not(r=-0.34). On the contrary, ${\Phi}(0)$ is highly correlated with scale value of annoyance and ${\Phi}(0)$ is need to be controlled as constant to find the effect of IACC on annoyance.

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