• Title/Summary/Keyword: Evaluation of correlations

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Development of Heat Transfer and Evaporation Correlations for the Turbulent Natural Convection in the Vertical Channel by Using Numerical Analysis

  • Kang, Han-Ok;Lee, Un-Chul
    • Nuclear Engineering and Technology
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    • v.28 no.6
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    • pp.532-541
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    • 1996
  • Theoretical and numerical study on heat transfer and evaporation in the vertical channel has been carried out and basic correlations have been derived for the heat transfer evaluation of PCCS. Analysis program was developed with low-Reynolds-number k-$\varepsilon$ model and surface transfer rates were calculated for the turbulent natural convection in the vertical channel. In relation to dry cooling by buoyancy-driven air, first, the system parameters which govern overall heat transfer rate are determined through the adequate nondimensionalization procedure. After comparison with existing experimental data, numerical results are used to derive heat transfer correlation by sensitivity calculations. In relation to wet cooling by falling water film, numerical analysis are carried out for evaporation process with real film surface conditions and evaporation correlation is derived through analogy concept and correction factors.

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An Evaluation of Empirical Prediction Equation for Deformation Modulus of Rock Masses by Field Measurements (암반변형계수의 현장시험을 통한 경험적 추정식의 적정성 평가)

  • Chun Byung-Sik;Lee Yong-Jae;Ahn Kyung-Chul;Shin Jae-Keun;Jung Sang-Hoon
    • Tunnel and Underground Space
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    • v.16 no.3 s.62
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    • pp.251-258
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    • 2006
  • In this paper, the applicability to the Korean rock condition of using the deformation moduli based on Rock Mass Rating (RMR) and Pressuremeter Test (PMT) is evaluated. The correlations among deformation moduli and various rock properties were also analyzed. It appears that the existing correlations using RMR overestimate the deformation moduli and wide variation was found between predicted moduli using these correlations and measured values. As for the correlations among the deformation moduli and various rock properties, Rock Quality Designation (RQD) and unconfined compressive strength (UCS) were found to correlate to deformation moduli reasonably well, but joint spacing and joint conditions appear to correlate poorly to RQD and UCS. Additionally, groundwater can not be correlated with the modulus values. While the depth has very little contribution to deformation modulus, it should be factored in the simple regression analyses with various rock mass properties, especially with the correlations made with UCS, RQD etc. With the deficiencies of these correlations, more in depth analysis techniques such as multivariate correlations may be to reliably estimate deformation modulus of rock mass.

The Effects of Ego Strength, Stress Coping Styles and Fear of Negative Evaluation on Children's Peer Relationships (자아강도, 스트레스 대처방식 및 부정적 평가에 대한 두려움이 아동의 교우관계에 미치는 영향)

  • Kim, Se Young;Choi, Naya
    • Korean Journal of Child Studies
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    • v.34 no.4
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    • pp.37-52
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    • 2013
  • This study was performed to model the effects of ego strength, stress coping styles, fear of negative evaluation, and the effects these concepts have upon children's peer relationships. Data were collected from 580 fifth and six graders in Seoul and Gyeonggi province. In summary, the results indicated the following. Firstly, there were significant correlations between ego strength, stress coping styles, fear of negative evaluation, and peer relationships. Secondly, the ego strength of children was found to have direct influences upon their stress coping styles, fear of negative evaluation and peer relationships. Thirdly, out of stress coping styles of children affected by ego strength, only the negative coping style was found to significantly influence the fear of negative evaluation and peer relationships. Fourth, the fear of negative evaluation on the part of children was affected by ego strength and negative stress coping styles, and in particular, negative stress coping styles influenced peer relationships through the anxiety induced from interpersonal relationships.

Evaluation of Urinary Nitrogen Excretion from Plasma Urea Nitrogen in Dry and Lactating Cows

  • Kume, S.;Numata, K.;Takeya, Y;Miyagawa, Y;Ikeda, S.;Kitagawa, M.;Nonaka, K.;Oshita, T.;Kozakai, T.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.8
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    • pp.1159-1163
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    • 2008
  • Data of 42 balance measurements from dry and lactating Holstein cows and blood and urine samples from 24 Japanese Black cows were collected to evaluate the potential for predicting urinary nitrogen (N) excretion from plasma urea nitrogen (PUN). Similar positive correlations were obtained between N intake and apparent N absorption in dry and lactating cows. The regression equations of N intake on urinary N excretion varied in dry and lactating cows, and the difference of urinary N excretion between dry and lactating cows was due to the N secretion into milk. Highly positive correlations were observed between urinary N contents and urinary urea N in Japanese Black cows, and urinary urea N increased with increasing PUN. There were positive correlations between N intake and PUN in dry and lactating cows, but PUN and urinary N excretion in lactating cows were higher than in dry cows. There were positive correlations between PUN and urinary N excretion per BW in dry and lactating cows. Although urinary N excretion could be calculated as (N clearance rate of kidneys)PUNBW, high N clearance rate of kidneys, such as 2.08 L/d/kg BW, may be suitable to calculate urinary N excretion in lactating cows, compared with 1.33 L/d/kg BW in dry cows.

Maternal and Direct Genetic Parameters for Production Traits and Maternal Correlations among Production and Feed Efficiency Traits in Duroc Pigs

  • Hoque, M.A.;Kadowaki, H.;Shibata, T.;Suzuki, K.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.7
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    • pp.961-966
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    • 2008
  • Direct and maternal genetic parameters for production traits in 1,642 pigs and maternal genetic correlations among production (1,642 pigs) and feed efficiency (380 boars) traits were estimated in 7 generations of a Duroc population. Traits studied were daily gain (DG), intramuscular fat (IMF), loineye area (LEA), backfat thickness (BF), daily feed intake (FI), feed conversion ratio (FCR) and residual feed intake (RFI). The RFI was calculated as the difference between actual and predicted feed intake. The predicted feed intake was estimated by adjusting the initial test weight, DG and BF. Data for production traits were analyzed using four alternative animal models (including direct, direct+maternal permanent environmental, or direct+maternal genetic+maternal permanent environmental effects). Direct heritability estimates from the model including direct and all maternal effects were $0.41{\pm}0.04$ for DG, $0.27{\pm}0.04$ for IMF, $0.52{\pm}0.06$ for LEA and $0.64{\pm}0.04$ for BF. Estimated maternal heritabilities ranged from $0.04{\pm}0.04$ to $0.15{\pm}0.05$ for production traits. Antagonistic relationships were observed between direct and maternal genetic effects ($r_{am}$) for LEA (-0.21). Maternal genetic correlations of feed efficiency traits with FI ($r_g$ of FI with FCR and RFI were $0.73{\pm}0.06$ and $0.90{\pm}0.05$, respectively) and LEA (rg of LEA with FCR and RFI were $-0.48{\pm}0.05$ to $-0.61{\pm}0.05$, respectively) were favorable. The estimated moderate genetic correlations between direct and maternal genetic effects for IMF and LEA indicated that maternal effects has an important role in these traits, and should be accounted for in the genetic evaluation system.

Genetic analysis of milk production traits of Tunisian Holsteins using random regression test-day model with Legendre polynomials

  • Zaabza, Hafedh Ben;Gara, Abderrahmen Ben;Rekik, Boulbaba
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.5
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    • pp.636-642
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    • 2018
  • Objective: The objective of this study was to estimate genetic parameters of milk, fat, and protein yields within and across lactations in Tunisian Holsteins using a random regression test-day (TD) model. Methods: A random regression multiple trait multiple lactation TD model was used to estimate genetic parameters in the Tunisian dairy cattle population. Data were TD yields of milk, fat, and protein from the first three lactations. Random regressions were modeled with third-order Legendre polynomials for the additive genetic, and permanent environment effects. Heritabilities, and genetic correlations were estimated by Bayesian techniques using the Gibbs sampler. Results: All variance components tended to be high in the beginning and the end of lactations. Additive genetic variances for milk, fat, and protein yields were the lowest and were the least variable compared to permanent variances. Heritability values tended to increase with parity. Estimates of heritabilities for 305-d yield-traits were low to moderate, 0.14 to 0.2, 0.12 to 0.17, and 0.13 to 0.18 for milk, fat, and protein yields, respectively. Within-parity, genetic correlations among traits were up to 0.74. Genetic correlations among lactations for the yield traits were relatively high and ranged from $0.78{\pm}0.01$ to $0.82{\pm}0.03$, between the first and second parities, from $0.73{\pm}0.03$ to $0.8{\pm}0.04$ between the first and third parities, and from $0.82{\pm}0.02$ to $0.84{\pm}0.04$ between the second and third parities. Conclusion: These results are comparable to previously reported estimates on the same population, indicating that the adoption of a random regression TD model as the official genetic evaluation for production traits in Tunisia, as developed by most Interbull countries, is possible in the Tunisian Holsteins.

Animal Model Versus Conventional Methods of Sire Evaluation in Sahiwal Cattle

  • Banik, S.;Gandhi, R.S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.9
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    • pp.1225-1228
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    • 2006
  • A total of 1,367 first lactation records of daughters of 81 sires, having 5 or more progeny were used to evaluate sires by 3 different methods viz., least squares (LS), best linear unbiased prediction (BLUP) and derivative free restricted maximum likelihood (DFREML) method. The highest and lowest overall average breeding value of sires for first lactation 305 days or less milk yield was obtained by BLUP (1,520.72 kg) and LS method (1,502.22 kg), respectively. The accuracy, efficiency and stability of different sire evaluation methods were compared to judge their effectiveness. The error variance of DFREML method was lowest ($191,112kg^2$) and its coefficient of determination of fitting the model was highest (33.39%) revealing that this method of sire evaluation was most efficient and accurate as compared to other methods. However, the BLUP method was most stable amongst all the methods having coefficient of variation (%) very near to unadjusted data (18.72% versus 19.89%). The higher rank correlations (0.7979 to 0.9568) between different sire evaluation methods indicated that there was higher degree of similarity of ranking sires by different methods ranging from about 80 to 96 percent. However, the DFREML method seemed to be the most effective sire evaluation method as compared to other methods for the present set of data.

Evaluation of Pumping Characteristics of High Strength Concrete using Continuous Pumping System

  • Kwon, Dae-Hun;Lee, Han-Seung;Jeon, Jun-Young;Jeong, Woong-Taek;Jo, Ho-Kyoo;Kim, Hyung-Rae
    • Journal of the Korea Institute of Building Construction
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    • v.11 no.4
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    • pp.387-395
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    • 2011
  • In the construction of tall-building, concrete pumping influences the success of the project. In order to establish pumping technology for high speed construction of tall building, study for quantitative evaluation of flow characteristics and pumpability should be conducted. So in this study, the characteristics including the inner pipe pressure, rheological properties of concrete and mortar through the continuous pumping test were evaluated. Then we analyzed the relations between rheological properties and pumpability. In the result of test, there are high correlations between the rheological characteristics which represented by yield stress and plastic viscosity and pressure loss with pipe length. Also, we estimated pressure loss according to conditions of concrete mix and pumping through the evaluation of inner pipe friction.

Characterization of Infiltration Analyses Using Long-Term Monitoring Flow Data (장기 모니터링 자료를 활용한 침입수 산정 방법론별 특성 분석)

  • Lee, Jaehyun;Kim, Insop;Oh, Jeill;Park, Chulhwi
    • Journal of Korean Society on Water Environment
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    • v.25 no.3
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    • pp.411-418
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    • 2009
  • The analysis of characteristics of water use evaluation and nighttime domestic flow evaluation was performed by using result from flow monitoring and surveying water supply records and nighttime domestic flow for a year. The analysis of correlations showed that, for both sites, the infiltration ratio and wastewater flow have shown a good relationship with high correlation factor and that the calculation of wastewater flow was highly affected by monthly rainfall depth as well as number of rain days. From this result, it was concluded that the measurement of infiltration should be performed when the rainfall does not significantly affect the sewer flow. Also, it is notable that each value of calculated using method for infiltration evaluation are not comparable to each other, but independent methods. In selecting of evaluation method for infiltration, therefore, a great emphasis should be imposed to the character of area and the seasonal factor in order to select optimal one. It is desirable way for evaluating infiltration and reduction ratio using result from an optimal method.

Nondestructive bending Strength Evaluation of Woodceramics Using Resonance Frequency Mode (I) - Carbonizing Temperature -

  • Byeon, Hee-Seop;Ahn, Sang-Yeol;Oh, Seung-Won;Piao, Jin-Ji
    • Journal of the Korean Wood Science and Technology
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    • v.32 no.3
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    • pp.8-14
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    • 2004
  • Nondestructive evaluation (NDE) technique method using a resonance frequency mode was carried out for woodceramics produced at different carbonizing temperatures (600℃, 800℃, 1000℃, 1200℃, 1500℃) at the phenol resin impregnation rate of 70%, for three kinds of species (Pinus densifora, Pinus koraiensis, Larix leptolepis), respectively. There was a poor relationship between density and static bending MOR. However, close correlations were found between dynamic MOEd and static bending MOR, and between static MOEs and MOR. Especially, the correlation coefficient was highest between MOEd and static bending MOR. Therefore, the MOEd using the resonance frequency mode is useful as a NDE method for predicting the MOR of woodceramics produced at different carbonizing temperatures.