• Journal of The Korean Society of Agricultural Engineers
• /
• v.58 no.1
• /
• pp.61-71
• /
• 2016

This study performed the physical and mechanical experiment on the samples of costal marine clays individually collected in western and southern regions to identify the characteristics of western and southern costal marine clay. Based on the experiment result, the characteristics of costal marine clay is identified undrained shear strength. Based on the experiment result on the physical and mechanical characteristics of costal marine clays, the regression is presented that can analyze the mechanical characteristics of undrained shear strength in costal marine clay of Korea, region of Korea and western-southern region. The correlation of uniaxial compressive strength and undrained shear strength was suitable for use of western-southern region correlation equation. The test result of Jeonnam Yeosu area compares with prediction results of previous researchers formula and western-southern region formula. Prediction results appear highest reliability on the 0.827 of coefficient of determination in the prediction results of the western-southern region formula.

• Computers and Concrete
• /
• v.6 no.3
• /
• pp.203-223
• /
• 2009

Regression analysis (RA) can establish an explicit formula to predict the strength of High-Performance Concrete (HPC); however, the accuracy of the formula is poor. Back-Propagation Networks (BPNs) can establish a highly accurate model to predict the strength of HPC, but cannot generate an explicit formula. Genetic Operation Trees (GOTs) can establish an explicit formula to predict the strength of HPC that achieves a level of accuracy in between the two aforementioned approaches. Although GOT can produce an explicit formula but the formula is often too complicated so that unable to explain the substantial meaning of the formula. This study developed a Backward Pruning Technique (BPT) to simplify the complexity of GOT formula by replacing each variable of the tip node of operation tree with the median of the variable in the training dataset belonging to the node, and then pruning the node with the most accurate test dataset. Such pruning reduces formula complexity while maintaining the accuracy. 404 experimental datasets were used to compare accuracy and complexity of three model building techniques, RA, BPN and GOT. Results show that the pruned GOT can generate simple and accurate formula for predicting the strength of HPC.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.3
• /
• pp.101-106
• /
• 2010

The purposes of this paper are to investigate an effect of weight of material and gender on postural stability and to introduce formulas for those. There were five levels of weights 0, 9, 18, 27 and 36 kg, and two levels of genders were conducted. Eight male and five female subjects participated in this experiment, ten tests were performed for each level of weights to measure the postural stability by using the stability platform. The effect of the genders and the load on the postural stability were statistically analysed by the two way ANOVA test and the regression analysis. The ANOVA test showed that the effect of weights was statistically significant on postural stability to the both male and female subjects. And the postural stability of female subjects was better than that of male subjects. A linear regression formula for the balancing time and the load and a formula for the reduction rate postural stability and the relative load were introduced by the regression analysis.

• Journal of the Society of Naval Architects of Korea
• /
• v.31 no.3
• /
• pp.112-118
• /
• 1994

In this paper, statistical approach to prediction of A-weighted noise level in ship cabins. based on multiple linear regression analysis, is conducted. The best regression formula is composed of seven parameters of the deadweight, the type of ship, the location of engines and cabins, the type of deckhouse and the propeller skew angle. Verification work was carried out with other 210 cabins' data in 6 ships. As a result, the formula ensures the accuracy of 3 dB(A) in 77 % of cases.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.20 no.2
• /
• pp.69-74
• /
• 2016

Purpose Using a regression formula of the trendline near the coefficient of determination (R2) "1" by substituting the dependent variable of the standard curve to calculate the values of the independent variable. To determine the suitability of a regression equation by comparing the difference between the independent variables of the standard curve and the predicted independent variables. Materials and Methods Perkin Elmer Gamma-Counter machine was used for Standard curve of regression methods. TSH. TG-Ag (Thyroglobulin Antigen), Insulin that used materials and method test to compare the result from the Excel trendline of the regression formula. Results Each of the value of coefficient of determination ($R^2$) and Trendline $R^2=1$, Polynomial Trendline for TSH, $R^2=1$, Polynomial Trendline for TG-Ag, $R^2=0.9994$, Polynomial Trendline for Insulin. Conclusion We confirmed that IRMA immune method is found to the nearest trends elected a standard curve using polynomial trendline. The independent variables to predict the trend by using a polynomial trendline formula containing the error was a limitation.

• Archives of Pharmacal Research
• /
• v.11 no.3
• /
• pp.185-196
• /
• 1988

The inflence of hydrophilic vehicles on percutaneous absorption rate of griseofulvin was studied using intact skin of full thickness of hairless rat. The in vitro absorption rates were used as the characteristics for deciding the optimum formula of ointment vehicles. The optimum formula of vehicle compositions for maximum absorption rate was obtained from the polynomial regression equation and the two graphical techniques, contour graph and partial derivative graph. It was composed of sodium lauryl sulfate (1.65 W /W%), white petrolatum (16.5 W /W%), propylene glycol (12.0 W /W%), and stearyl alcohol (19.6W /W%). The experimental value obtained from the optimum formula and the prediction value were 33.99 and 33.87 ${\mu}g/\sqrt{min}$, respectively. From these results, it was believed that optimum formula for semisolid dosage forms could be obtained from the application of the optimization technique used in this study.

• Journal of Wetlands Research
• /
• v.2 no.1
• /
• pp.49-58
• /
• 2000

The frequency analysis of annual maximum rainfall data and the derivation of probable rainfall intensity formula at Masan station are performed in this study. Based on the eight different rainfall duration data from 10 minutes to 24 hours, eight types of probability distribution (Gamma, Lognormal, Log-Pearson type III, GEV, Gumbel, Log-Gumbel, Weibull, and Wakeby distributions), three types of parameter estimation scheme (moment, maximum likelihood and probability weighted methods) and three types of goodness-of-fit test (${\chi}^2$, Kolmogorov-Smirnov and Cramer von Mises tests) were considered to find an appropriate probability distribution at Masan station. The Lognormal-2 distribution was selected and the probable rainfall intensity formula was derived by regression analysis. The derived formula can be used for estimating rainfall quantiles of the Masan vicinity areas with convenience and reliability in practice.

• Journal of Korea Water Resources Association
• /
• v.47 no.9
• /
• pp.743-752
• /
• 2014

Delay time for groundwater recharge means the travel time from the bottom of soil layer to groundwater through vadose zone after infiltration from rainfall. As it is difficult to measure delay time, we suggested an empirical formula which is derived by using linear regression between altitude and delay time. For the regression analysis, 4 major gauging watersheds were chosen (Hancheon, Kangjeongcheon, Oedocheon, Cheonmicheon) with 18 measured groundwater level stations. To verify this empirical formula, derived equation from linear reservoir theory was applied to compute delay time and to compare estimated amounts of groundwater recharge using both methods. The result showed good agreement. Furthermore, if derived empirical formula would be linked with SWAT model, the spatial time delay effect in the watershed could be reflected properly.

• Journal of the Korean Statistical Society
• /
• v.11 no.1
• /
• pp.59-68
• /
• 1982

We propose that, in order to control the inflation and general instability associated with the least squares estimates, we can use the ridge estimator $$ \hat{B}^* = (X'X+kI)^{-1}X'Y : k \leq 0$$ for the regression coefficients B in multivariate regression. Our hope is that by accepting some bias, we can achieve a larger reduction in variance. We show that such a k always exists and we derive the formula obtaining k in multivariate ridge regression.

• Journal of the Korean Data and Information Science Society
• /
• v.27 no.6
• /
• pp.1585-1592
• /
• 2016

Estimation of winning percentage in baseball has always been particularly interesting to many baseball fans. We have fitted models including linear regression and Pythagorean formula to the Korean baseball data of seasons from 1982 to 2015. Using RMSE criterion for both the linear formula and the Pythagorean formula, we compared two models in predicting the actual winning percentage. Pythagorean expectation is superior to linear formula when there is either high or low winning percentage. Two methods yield very similar efficiencies when the actual winning percentage is about 50%. To understand and use for estimating winning percentage, it is easier linear formula as estimated equations.