• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.981-985
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• 1987

In this paper, we predicted the quantities of ass output messages with the generalized estimation equation based on regression model. And, to know the generalization of equation, we measured the deviation of errors between the observed and the estimated values. As a result, the proposed equation applied to sample data showed linear characteristics in some cases.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.697-702
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• 1999

Among several non-destructive testing methods, ultrasonic pulse velocity method has been widely used for the evaluation of concrete strength. However, this method might not provide accurate estimated results since factors influencing the relationship between strength and wave velocity is not considered. In this study, the evaluation methods of concrete strength using compression wave velocities measured by either ultrasonic pulse velocity method or impact-resonance method are proposed. A basic equation is obtained by the linear regression with velocity vs. strength data at a specific age and then, ageing factor is employed in the equation to consider the difference of the increasing rate between wave velocity and strength. Strengths predicted by the proposed equation agree well with test results.

• Journal of the Korea Concrete Institute
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• v.11 no.4
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• pp.157-167
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• 1999

Among several non-destructive testing methods, ultrasonic pulse velocity method and rebound index method have been widely used for the evaluation of concrete strength. However, such methods might not provide accurate estimated results since factors influencing the relationship between strength and either ultrasonic pulse velocity or rebound index are not considered. In this paper, the evaluation method of concrete strength using rod-wave velocity measured by impact-resonance method is proposed. A basic equation is obtained by the linear regression of velocity vs, strength data at specific age and then, aging factor is employed in the equation to consider the difference of the increasing rate between wave velocity and strength. Strengths predicted by the proposed equation agree well with test results. Furthermore, the combined method of rod-wave velocity and rebound index is proposed.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2005.10a
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• pp.614-619
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• 2005

The object of this study was to presented regression equations for obtaining simply and quickly values of water quality items, BOD, COD, T-N, and T-P. Regression equations obtained to analyze relationships for water quality items to land use types in agricultural reservoir watersheds. In order to derive regression equations, a multiple linear regression analysis was used in this studying reservoirs. In this regression analysis, a independent values used land used types and dependent values used BOD, COD, T-N, T-P values in water quality items. The results showed that numbers of regression equation ranging above 0.90 in a multiple correlation coefficient (MCC) was not found, ranging from 0.70 to 0.90 in the MCC was 6, ranging from 0.40 to 0.70 in the MCC was 20, and ranging from 0.20 to 0.40 in the MCC was 4. The results of this study can be used as a basic information for evaluating simply and quickly water quality for proposing and designing steps in water quality policy.

• Journal of Environmental Health Sciences
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• v.17 no.1
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• pp.95-103
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• 1991

For the purpose of estimating the working environment and the relationship between the airborne lead concentration and the ZPP level in the whole blood of the workers, the airborne lead concentrations and the ZPP level were measured at the 26 plants which deal with lead, from October 5 to November 5 in 1988. Analysis of the airborne lead concentration was performed by NIOSH Method 7082, and the ZPP level was measured by a hematofluorometer. The following results are concluded. 1. The average airborne lead concentration of the lead battery manufactures is 0.025mg/m$^{3}$ and that of the secondary lead smelters is 0.023mg/m$^{3}$. There were no significant differences between industry (p>0.1) 2. At the lead battery manufacture, the process of lead powder production showed the highest concentration of 0.034mg/m$^{3}$ but there were no significant differences among the processes (p>0.1). At the secondary lead smelter, the process of dismantling waste batteries showed the highest concentration 0.141mg/m$^{3}$, and there were very significant differences among the processes (p<0.005). 3. The ZPP level in the whole blood showed significant differences between industry (p<0.10). The average ZPP level of the lead battery manufactures is 133.0 + 106.3 $\mu$g/100ml and that of the secondary lead smelters is 149.6 + 110.9 $\mu$g/100ml. 4. The correlation coefficients between the airborne lead concantration and ZPP level were 0. 426 (p<0.001) for the lead battery manufactures and 0.484 (p<0.001) for the secondary lead smelters. The correlation coefficients between the work duration (in months) and the ZPP level were 0.238 (p<0.001) for the lead battery mannfactures and 0.075 (p>0.10) for the secondary lead smelters. 5. The linear regression equation, with the airborne lead concentration as an independent variable and the ZPP level as a dependent variable, is Y=96.84+1300.34X (r=0.448, p<0.001) for the 26 plants which deal with lead. The linear regression equation, with the work duration(in months) as an independent variable and the ZPP level as a dependent variable, is Y=127.28 +0.49X (r=0.162, p<0.05). 6. The correlation coefficients between the amount of inhaled lead and ZPP level were 0.349 (p < 0.001) for the lead battery manufactures and 0.318(p<0.001) for the secondary lead smeltes. The linear regression equation for the 26 plants surveyed, with the amount of inhaled lead as an independent variable and ZPP level as a dependent variable, is Y=123.63+18.82X (r=0. 335, p<0.001).

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.11 no.3
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• pp.235-240
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• 2001

This study was performed to compare the lead levels of 20 quality control standard samples(KOSHA:18-2000) and 72 field samples in lead-acid battery manufacturing plant between ICP and portable-XRF methods. 1. While the proficiencies of 20 quality control standard samples by ICP were 100%, those of analytic result values by XRF were 75%. 2. The correlation coefficient(r) between the reference values for quality control (REF) and the analytic result values by ICP (ICP) was 1.0(p<0.05), and simple linear regression equation and the coefficient(R2) were REF = -0.0009 + 1.016 ICP and 0.9997, respectively. 3. The correlation coefficient(r) between the analytic result values of quality control standard samples by ICP (ICP) and by XRF (XRF) was 0.975(p<0.05), and simple linear regression equation and the coefficient(R2) were ICP = -0.0003 + 1.002 XRF and 0.950, respectively. 4. The correlation coefficient(r) between the analytic result values for lead samples of a lead-acid battery manufacturing plant by ICP (ICP) and by XRF (XRF) was 0.993(p<0.05), and simple linear regression equation and the coefficient(R2) were ICP = -2.058 + 0.996 XRF and 0.987, respectively. 5. While the frequency distributions of XRF /ICP(Ratio) for each ICP concentration levels in a lead-acid battery manufacturing plant revealed high proportion in ratio range of 0.876-1.125 than in ration range of 1.126-1.375. Also, ICP concentration level in ration range of 0.786-1.125 was increased with increase of frequency distribution of XRF/ICP. 6. The limit of detection of XRF on lead was determined to be $6.11{\mu}g$/filter The data presented in this study indicated that relationship for lead level of quality control samples and field samples in a lead -acid battery manufacturing plant by ICP and portable-XRF methods was proved. The practicing industrial hygienist can use portable-XRF to produce a rapid on-site determination of lead exposure that can immediately becommunicated to workers and help identify appropriate levels of personal protection.

• Journal of Environmental Science International
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• v.23 no.3
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• pp.387-397
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• 2014

This study is carried out to propose an empirical equation which can promptly predict the aircraft noise level at a specific point (a receptor) near Jeju international airport by using the information of the flight path data. For this purpose, Analyses of multiple linear regression with the slant distances (SD) calculated from the gate analyses of the flight path data, aircraft noise certification levels with unit of EPNL(effective perceived noise level) and noise levels measured at receptors are performed by SPSS package. From these regression analyses for approach and departure of aircraft, we can propose empirical equations which is statistically significant. The noise levels predicted by these empirical equations are highly correlated the measured data.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.29 no.1
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• pp.143-150
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• 2006

Box-Cox model and T-factor method have been widely used to measure economic depreciations for industrial property. The Box-Cox model which combines economic efficiency with depreciation pattern is here extended to the reliability function. To do so a Rayleigh distribution which has been used to estimate the reliability of current assets was chosen as an efficiency curve of marginal productivity. Such an approach provides the possibility to classify the efficiency curves into four categories. It is also possible to analyze the types of depreciation curves. Therefore, the power family of a non-linear Box-Cox model could be set at certain constant values, then the model can be transformed into a linear model to estimate the economic depreciation rates by utilizing the reliability function. Estimating the resultant linear regression equation requires minimal number of observations, while at the same time facilitating the test of hypothesis on depreciation rates.

• Transactions of Materials Processing
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• v.30 no.2
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• pp.74-82
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• 2021

Stretch-flangeability, which is the ability of sheet steels to be deformed into complex shapes, is a critical formability property in automobile body parts. In this study, the center-hole for hole expansion test, which is normally used to evaluate the stretch-flangeability of sheet steels, was prepared by both punching and electrical discharge machining (EDM) methods. Hole expansion ratio (HER) of punched hole was far lower than the HER of EDM drilled hole because of damage/crack in hole-edge due to punching process. The effect of hole-edge condition on HER was quantified by mechanical, fractographic and geometric factors. Based on these factors, the empirical equation used to determine HER for various sheet steels was derived using non-linear regression.

• Textile Coloration and Finishing
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• v.11 no.5
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• pp.38-43
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• 1999

A calculation method of optimum parameters on dual adsorption isotherm system was examined. The optimum parameters were obtained by non-linear regression analysis based upon a limited solute concentration of dual adsorption isotherm. The results were analyzed with adducing experimental data of formerly reported treaties. The percentage mean deviation of dual adsorption equation calculated with optimum parameters was less than about 5% of experimental data, which was far less than results obtained with parameters of the adduced treatises.