• Korean Journal of Health Education and Promotion
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• 제27권2호
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• pp.121-139
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• 2010

Objectives: The purpose of this study was to identify the health promotion activities of the elderly Korean aged 65 or older and to examine the related factors associated with the health promotion activities. Methods: Data were obtained from 2008 Social Statistics Survey of Korea National Statistical Office of 6,207 people aged 65 or older. We measured the socio-demographic characteristics, physical health status, social health status, and health promotion activities. Statistical analyses were employed through the $X^2$-test and Odds ratio using Logit Model. Results: In our study, health promotion activity practice rates were varied among the socio-demographic characteristics, physical and social health status. Our findings also support that better socio-demographic and physical health status explain the higher practice rates of health promotion activities. In addition, the higher social health status was associated with better practice rates of health promotion activities. Conclusion: We found that the health promotion activities of the elderly could be encouraged by better socio-demographic status and physical and social health status. To better accomplish the health promotion for the elderly in our community, policy-makers should need careful political deliberation for executing health promotion services considering the distinctions of programme and target groups.

• Journal of Family Resource Management and Policy Review
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• 제21권4호
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• pp.35-59
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• 2017

The purpose of this study was to explore the changes in adolescents' time use and time famine between 2004~2014. The data sources were the Time Use Surveys, which were conducted by the Korea National Statistical Office in 2004 and 2014. A total of 15,386 time diaries (9,008 from 2004, 6,378 from 2014) from adolescents aged between 10 and 18 were analyzed. Descriptive statistics, chi-square, t-test were used for the statistical analyses. The main findings were as follows: First, the necessary time of adolescents was more in 2014 compared to 2004. In particular, adolescents' sleeping time increased on Saturdays. Second, on weekdays and Saturdays, the school hours of adolescents was less in 2014 compared to 2004. But extra school hours of adolescents were more on Saturdays. Third, adolescents had more leisure time on Saturdays but less leisure time on Sundays in 2014 than 2004. Fourth, the average time famine score was lower in 2014 compared to 2004. Even so, the score for high school students was higher than 3 in 4 point Likert scale. This study provides a data-base on the well-being of adolescents and the education policies that affect them.

• Journal of Welding and Joining
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• 제25권4호
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• pp.58-64
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• 2007

Recently, the electro-magnetic induction process has been utilizing to substitute the flame heating process in shipyard. However, few studies have been performed to exactly analyze the deformation mechanism of the heating process with mathematical model. This is mainly due to the difficulty of modeling the inductor travelling on plate during the process. In this study, heat flux distribution of the process is firstly numerically analysed with the assumption that the process has a quasi-stationary state and also with the consideration that the heat source itself highly depends on the temperature of base plate. With the heat flux, the thermal and deformation analyses are then performed with a commercial program for 34 combinations of heating parameters. The deformations obtained and heating parameters are synthesized with a statistical method to produce simplified formulas, which easily give the relation between the heating parameters and deformations. The formulas are well compared with results of experiment.

• Journal of Korean language education
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• 제28권4호
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• pp.87-119
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• 2017

The purpose of this study is to classify research methods used in Korean language education studies with a focus on identifying how and what quantitative research methods are utilized in these studies. Analyzing articles published in the Journal of Korean Language Education from 2005 to 2016, we found a trend that as a replacement for secondary research, primary research played a more prominent role after 2010, as the number of quantitative studies and studies using mixed methods increased. We also found that within quantitative studies of Korean language education, research themes and statistical analyses became diversified after 2010. In order for quantitative research to contribute continuously to Korean language education, the quality of research has to improve. In particular, quantitative researchers in this area should: (a) increase their general understanding of statistical methods, (b) conduct "power analysis" to determine the appropriate sample size for hypothesis testing, and (c) be aware of measurement issues such as measurement equivalence and DIF when measuring latent psychological constructs. It is also important to notice that these points above should be considered carefully in the planning and designing stage for researchers.

• PNF and Movement
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• 제18권1호
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• pp.133-141
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• 2020

Purpose: The purpose of this study was to conduct balance training through vision control to improve the balance, postural control, and balance confidence and to decrease the visual and sensory dependence of stroke patients. Methods: Twenty-eight chronic stroke patients volunteered to participate in the study. They were randomly assigned to the eyes-closed and the eyes-open training groups. Three times a week for four weeks each group performed an unstable-support session and a balance training session for thirty minutes per set. Their balance, postural control, and balance confidence were assessed using BIO Rescue (BR), the postural assessment scale for stroke (PASS), and the Korean activity-specific balance confidence scale (K-ABC), respectively. All data were analyzed using SPSS version 22.0. Statistical methods before and after working around the average value of each dataset were independent T-test. The significance level for statistical analyses was set at 0.05. Results: Comparison between the groups showed statistically significant effects on all variables before and after the intervention (p < 0.05). Conclusion: This study reflected that balance-training programs involving vision control improve the balance, postural control, and balance confidence of chronic stroke patients. Thus, stroke patients should undergo training programs that increase the use of their other senses with vision control in clinical practice.

• Structural Engineering and Mechanics
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• 제60권6호
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• pp.953-977
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• 2016

Modern performance-based design methods require ways to determine the factual behavior of structures subjected to earthquakes. Drift ratio demands are important measures of structural and/or nonstructural damage of the structures in performance-based design. In this study, global drift ratio and interstory drift ratio demands, obtained by nonlinear time history analysis of three generic RC frames using code-compatible ground motion record sets, are statistically evaluated. Several ground motion record sets compatible with elastic design spectra defined for the local soil classes in Turkish Earthquake Code are used for the analyses. Variation of the drift ratio demands obtained from ground motion records in the sets and difference between the mean of drift ratio demands calculated for ground motion sets are evaluated. The results of the study indicate that i) variation of maximum drift ratio demands in the sets were high; ii) different drift ratio demands are calculated using different ground motion record sets although they are compatible with the same design spectra; iii) the effect of variability due to random causes on the total variability of drift ratio demands is much larger than the effect of variability due to differences between the mean of ground motion record sets; iv) global and interstory drift ratio demands obtained for different ground motion record sets can be accepted as simply random samples of the same population at %95 confidence level. The results are valid for all the generic frames and local soil classes considered in this study.

• Journal of Soil and Groundwater Environment
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• 제26권6호
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• pp.186-195
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• 2021

In Korea, groundwater quality is monitored through National Groundwater Quality Monitoring Network (NGQMN) administered by Ministry of Environment. For a given contaminant, compliance to groundwater quality standards is assessed on a annual basis by monitoring the number of incidents that concentration exceeds the regulatory limit. However, this approach provides only a fractional information about groundwater quality degradation, and more crucial information such as location and severity of the contamination cannot be obtained. For better groundwater quality management on a watershed, a more spatially informative and intuitive method is required. This study presents two statistical methods to convert point-wise monitoring data into information on groundwater quality status of a watershed by using a proposed grading scale. The proposed grading system is based on readily available reference standards that classify the water quality into 4 grades. The methods were evaluated with NO₃^-, Cl^-, and total coliform data in Geum River basin. The analyses revealed that groundwater in most watersheds of Geum River basin is good for domestic or/and drinking with no treatment. But, there was notable quality degradation in Bunam seawall and So-oak downstream standard watersheds contaminated by NO₃^- and Cl^-, respectively.

• Communications for Statistical Applications and Methods
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• 제26권5호
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• pp.445-461
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• 2019

It is possible that data are not always fitted with sufficient precision by the existing distributions; therefore this article presents a methodology that enables the use of families of asymmetric distributions as alternative probabilistic models for survival analysis, with censorship on the right, different from those usually studied (the Exponential, Gamma, Weibull, and Lognormal distributions). We use a more flexible parametric model in terms of density behavior, assuming that data can be fit by a distribution of stable distribution families considered unconventional in the analyses of survival data that are appropriate when extreme values occur, with small probabilities that should not be ignored. In the methodology, the determination of the analytical expression of the risk function h(t) of the $L{\acute{e}}vy$ distribution is included, as it is not usually reported in the literature. A simulation was conducted to evaluate the performance of the candidate distribution when modeling survival times, including the estimation of parameters via the maximum likelihood method, survival function ${\hat{S}}$(t) and Kaplan-Meier estimator. The obtained estimates did not exhibit significant changes for different sample sizes and censorship fractions in the sample. To illustrate the usefulness of the proposed methodology, an application with real data, regarding the survival times of patients with colon cancer, was considered.

• Communications for Statistical Applications and Methods
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• 제26권3호
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• pp.325-336
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• 2019

In this article we extend the discrete Weibull regression model in the presence of missing data. Discrete Weibull regression models can be adapted to various type of dispersion data however, it is not widely used. Recently Yoo (Journal of the Korean Data and Information Science Society, 30, 11-22, 2019) adapted the discrete Weibull regression model using single imputation. We extend their studies by using multiple imputation also with several various settings and compare the results. The purpose of this study is to address the merit of using multiple imputation in the presence of missing data in discrete count data. We analyzed the seventh Korean National Health and Nutrition Examination Survey (KNHANES VII), from 2016 to assess the factors influencing the variable, 1 month hospital stay, and we compared the results using discrete Weibull regression model with those of Poisson, negative Binomial and zero-inflated Poisson regression models, which are widely used in count data analyses. The results showed that the discrete Weibull regression model using multiple imputation provided the best fit. We also performed simulation studies to show the accuracy of the discrete Weibull regression using multiple imputation given both under- and over-dispersed distribution, as well as varying missing rates and sample size. Sensitivity analysis showed the influence of mis-specification and the robustness of the discrete Weibull model. Using imputation with discrete Weibull regression to analyze discrete data will increase explanatory power and is widely applicable to various types of dispersion data with a unified model.

• The Journal of Industrial Distribution & Business
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• 제12권9호
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• pp.7-18
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• 2021

Purpose: This study aims to investigate whether there is a difference in the prevalence of hypertension according to gender, occupational group, and occupational group according to gender. Research design, data, and methodology: This study classified the occupational groups according to the gender of men and women between the ages of 20 and 49 into office workers and non-office workers from the 7th 2017 National Health and Nutrition Examination Survey. A total of 2,691 people were surveyed, including 1,394 office workers and 1,297 non-office workers. Frequency analysis, chi-square, and Independent T-test for distribution difference analysis of categorical variables analysis for occupation and hypertension were applied. Statistical significance was verified at 0.001 to determine the validity analysis. All statistical analyses were performed using the IBM SPSS 24.0 program. Results: The main risk factors for hypertension were gender, age, education, obesity, smoking, drinking, family history, and chronic diseases. There were differences in the prevalence of hypertension among office workers and non-office workers. Conclusions: Men had a higher prevalence of hypertension than women, while non-office workers had a higher prevalence than office workers. In the case of women, non-office workers have a higher prevalence of hypertension than white-collar workers.