• Proceedings of the Korea Water Resources Association Conference
• /
• 2002.05b
• /
• pp.1334-1339
• /
• 2002

The objective of this study is to help practicing engineers easily use the Clark model which is used for estimating the magnitude of design flood for small stream. A representative unit hydrograph was derived on the basis of the past rainfall-runoff data and unit hydrographs, and the storage coefficient of Clark model was estimated by using hydrograph recession analysis. Since the storage coefficient(K) is a dominating factor among the parameters of Clark method, a mulitple regression formula, which has the drainage area, main channel length and slope as parameters, is propsed to estimate K value of a basin where measured data are missing. The result of regression analysis showed that there is a correlation between a storage coefficient(K) and aforemetioned three parameters in homogenious basins. A regression formular for K was derived using these correlations in a basin of Han River, Nakdong River, Young River, Kum River and Sumjin River

• Journal of Family Relations
• /
• v.20 no.4
• /
• pp.131-156
• /
• 2016

Objective: This study aimed to examine parenting education participation of Korean mothers in the transition to parenthood and its related variables. Method: A study sample was composed of 870 mothers whose first child was younger than one-year old from the Panel Study on Korean Children in 2008(mean age=30.1, SD = 3.69). The descriptive statistics of parenting education participation were presented. In addition, negative binomial and logistic regression models were used in Stata13 in order to examine the variables related to parenting education participation of mothers in the transition to parenthood. Results: Approximately 82% of the mothers reported that they had participated in at least one parenting education program. Further, mother's educational level, monthly household income, mother's working experience, and community type generally predicted parenting education participation of mothers. However, the effects of these variables varied by the subjects and the providing institutions. Conclusion: This study provides the overall picture of parenting education participation of Korean mothers in the transition to parenthood and its related variables. The findings can be utilized to plan more effective parenting education programs for new parents.

• Toxicological Research
• /
• v.30 no.1
• /
• pp.7-11
• /
• 2014

Malondialdehyde (MDA), used as an oxidative stress marker, is commonly assayed by measuring the thiobarbituric acid reactive substances (TBARS) using HPLC, as an indicator of the MDA concentration. Since the HPLC method, though highly specific, is time-consuming and expensive, usually it is not suitable for the rapid test in large-scale environmental epidemiologic surveys. The purpose of this study is to develop a simple and rapid method for estimating TBARS levels by using a multiple regression equation that includes TBARS levels measured with a microplate reader as an independent variable. Twelve hour urine samples were obtained from 715 subjects. The concentration of TBARS was measured at three different wavelengths (fluorescence: ${\lambda}-_{ex}$ 530 nm and ${\lambda}-_{em}$ 550 nm; ${\lambda}-_{ex}$ 515 nm and ${\lambda}-_{em}$ 553 nm; and absorbance: 532 nm) using microplate reader as well as HPLC. 500 samples were used to develop a regression equation, and the remaining 215 samples were used to evaluate the validity of the regression analysis. The induced multiple regression equation is as follows: TBARS level (${\mu}M$) = -0.282 + 1.830 ${\times}$ (TBARS level measured with a microplate reader at the fluorescence wavelengths ${\lambda}-_{ex}$ 530 nm and ${\lambda}-_{em}$ 550 nm, ${\mu}M$) -0.685 ${\times}$ (TBARS level measured with a microplate reader at the fluorescence wavelengths ${\lambda}-_{ex}$ 515 nm and ${\lambda}-_{em}$ 553 nm, ${\mu}M$) + 0.035 ${\times}$ (TBARS level measured with a microplate reader at the absorbance wavelength 532 nm, ${\mu}M$). The estimated TBARS levels showed a better correlation with, and are closer to, the corresponding TBARS levels measured by HPLC compared to the values obtained by the microplate method. The TBARS estimation method reported here is simple and rapid, and that is generally in concordance with HPLC measurements. This method might be a useful tool for monitoring of urinary TBARS level in environmental epidemiologic surveys with large sample sizes.

• Journal of the Korean Data and Information Science Society
• /
• v.22 no.1
• /
• pp.65-71
• /
• 2011

Path analysis is a useful method to find out direct or indirect effects between variables. Compared to regression analysis for studying the casual relationship, this method has a good advantage. In this study, I want to figure out direct or indirect relationships between golf skills and adjust average scores using path analysis. To analyze data, I applied AMOS in SPSS and collected data in 2010 PGA.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.9
• /
• pp.127-134
• /
• 2004

It is difficult to have the existing structural optimization using coupled field analysis from CFD to structure analysis when the structure is influenced of fluid. Therefore in an initial model of this study after doing parameter design from the background of shape using topology optimization. and it is making a approximation formula using by the CFD-structure coupled-field analysis and design of experiment. By using this result, we conducted multi-objective optimization. We could confirm efficiency of stochastic method applicable in the scene of structure reliability design to be needed multi-objective optimization. And we presented a way of design that could overcome the time and space restriction in structural design such as the butterfly valve with the less experiment.

• Journal of Preventive Medicine and Public Health
• /
• v.54 no.3
• /
• pp.166-172
• /
• 2021

Traditional epidemiological assessments, which mainly focused on evaluating the statistical association between two major components-the exposure and outcome-have recently evolved to ascertain the in-between process, which can explain the underlying causal pathway. Mediation analysis has emerged as a compelling method to disentangle the complex nature of these pathways. The statistical method of mediation analysis has evolved from simple regression analysis to causal mediation analysis, and each amendment refined the underlying mathematical theory and required assumptions. This short guide will introduce the basic statistical framework and assumptions of both traditional and modern mediation analyses, providing examples conducted with real-world data.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.29 no.2 s.233
• /
• pp.303-310
• /
• 2005

The systems with probe and SIL(Solid Immersion Lens) mechanisms have been researched as the technology to perform NFR(Near Field Recording). Most of them use the flying head mechanism to accomplish high recording density and fast data transfer rate. In this paper, ABS shape of flying head was optimized with the object of securing the maximum compliance ability of OFH. We suggest low different optimization processes to predict the static flying characteristics for the OFH. Two different approximation methods, regression analysis and back propagation neural network were used. And we compared the result of directly connected(between CAE and optimizer) method and two approximated optimization results. Design Optimization Tool(DOT) and ${\mu}GA$ were used as the optimizers.

• Journal of the Korean Home Economics Association
• /
• v.41 no.10 s.188
• /
• pp.117-128
• /
• 2003

This study investigated the consumers' awareness and information needs towards foodborne illness. Data were collected from 504 adults in Seoul, Daegu and Busan by the self-administered questionnaire. Frequencies, $X^2$ test and regression analysis were conducted by SPSS Windows. The results of this study were as follows: (1) the consumers' concerns and information needs about foodborne illness were generally high, (2) about four-fifths of the subjects were extremely worried about foodborne illness caused by fish, (3) about two-thirds answered that the major factor of foodborne illness in cooking was unfreshed or contaminated food stuffs, (4) the respondents primarily wanted to get the information about the method to choose fresh food, and (5) the result of the regression analysis showed educational attainment and concerns about foodborne illness were the factors affecting the consumers' information needs.

• Journal of Korean Academy of Nursing
• /
• v.37 no.4
• /
• pp.594-602
• /
• 2007

Purpose: This study was conducted to investigate the correlation among uncertainty, mastery and appraisal of uncertainty in hospitalized children's mothers. Method: Self report questionnaires were used to measure the variables Variables were uncertainty, mastery and appraisal of uncertainty. In data analysis, the SPSSWIN 12.0 program was utilized for descriptive statistics, Pearson's correlation coefficients, and regression analysis. Result: Reliability of the instruments was cronbach's $alpha=.84{\sim}.94$. Mastery negatively correlated with uncertainty(r=-.444, p=.000) and danger appraisal of uncertainty(r=-.514, p=.000). In regression of danger appraisal of uncertainty, uncertainty and mastery were significant predictors explaining 39.9%. Conclusion: Mastery was a significant mediating factor between uncertainty and danger appraisal of uncertainty in hospitalized children's mothers. Therefore, nursing interventions which improve mastery must be developed for hospitalized children's mothers.

• The Korean Journal of Applied Statistics
• /
• v.11 no.1
• /
• pp.97-111
• /
• 1998

This paper suggests a Bayesian method for testing first-order markov correlation among linear regression disturbances. As a Bayesian test criterion, Bayes factor is derived in the form of generalized Savage-Dickey density ratio that is easily estimated by means of posterior simulation via Gibbs sampling scheme. Performance of the Bayesian test is evaluated and examined based upon a Monte Carlo experiment and an empirical data analysis. Efficiency of the posterior simulation is also examined.