• Journal of Korea Water Resources Association
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• v.49 no.8
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• pp.645-656
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• 2016

The study performed a regional flood frequency analysis and proposed a regression equation to estimate design floods corresponding to return periods for ungauged basins in Geum-river basin. Five preliminary tests were employed to investigate hydrological independence and homogeneity of streamflow data, i.e. the lag-one autocorrelation test, time homogeneity test, Grubbs-Beck outlier test, discordancy measure test ($D_i$), and regional homogeneity measure (H). The test results showed that streamflow data were time-independent, discordant and homogeneous within the basin. Using five probability distributions (generalized extreme value (GEV), three-parameter log-normal (LN-III), Pearson type 3 (P-III), generalized logistic (GLO), generalized Pareto (GPA)), comparative regional flood frequency analyses were carried out for the region. Based on the L-moment ratio diagram, average weighted distance (AWD) and goodness-of-fit statistics ($Z^{DIST}$), the GLO distribution was selected as the best fit model for Geum-river basin. Using the GLO, a regression equation was developed for estimating regional design floods, and validated by comparing the estimated and observed streamflows at the Ganggyeong station.

• Journal of the Korea Convergence Society
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• v.10 no.9
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• pp.291-299
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• 2019

The purpose of this study is to identify the effects of laughter therapy on healthy life of human through meta-analysis of literature. Based on domestic and foreign academic databases, 495 foreign and 199 domestic literature were reviewed focusing on "quality of life," as the ultimate goal of health. The final seven literature were extracted. Analyses was performed in R version 3.5.1. Significant differences (SMD=0.23, p<0.01) were shown in the pre-post comparisons of experimental groups using the mean difference (effects size) analysis of the extracted samples. Significant results were not shown in meta regression analyses setting explanatory variables as 'treatment sessions and durations' and outcome variables as 'treatment effects of laughter therapy'. This study is meaningful in comparative analyses of pre-post experimental groups to establish 'laughter therapy' has a significant effect on improving 'quality of life' and is a useful intervention method, especially for older people, and older women with depression.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.676-686
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• 2016

This study analyzed the long term relationship between the K-REITs' lending rate and interest rate variables based on ARDL (autoregressive distributed lag) and also examined the short term relationship based on the ARDL-ECM model. In the results of the empirical test, there is a co-integration relationship among the K-REITs' lending rate, 3 year government bond (rate), 3 year government bond (rate), corporation bond (rate) (AA-, 3year) and general fund loan rate. This means that the K-REITs' lending rate is related to the long term interest rate. The corporate general fund loan rate has a significant correlation with the K-REITs' lending rate in the long term relation and short term adjustment process. The establishment of a management plan by the REITs considering the trends in the corporate general fund loan rate in the decision making process for finance sector borrowings can be practically helpful for the K-REITs.

• Korea Science and Art Forum
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• v.29
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• pp.189-201
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• 2017

The purpose of this study is to identify the factors that constitute the memorable tourism experiences and to grasp the influence relationship between the memorable tourism experience and the tourism destination brand equity and the loyalty of the tourism destination. The scope and method of the research are derived from the survey data collected through the questionnaire survey for foreign tourists who are visiting Korea, the reliability analysis and the feasibility analysis are conducted, and the relationship between the factors is analyzed through regression analysis. The results of this study are as follows. First, the results of the study are as follows. First, the results of the study are as follows. First, Interested exotic experiences, experience with local guides, and local residents' hospitality experience were found to have a significant effect on tourism destination brand assets. Based on this, And provided practical implications.

• Journal of the Korean Association of Geographic Information Studies
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• v.15 no.1
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• pp.16-33
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• 2012

The aim of this study is to estimate aboveground biomass carbon stocks using ordinary kriging(OK) which is the most commonly used type of kriging and regression kriging(RK) that combines a regression of the auxiliary variables with simple kriging. The analysis results shows that the forest carbon stock in Danyang is estimated at 3,459,902 tonC with OK and 3,384,581 tonC with RK in which the R-square value of the regression model is 0.1033. The result of RK conducted with sample plots stratified by forest type(deciduous, conifer and mixed) shows the lowest estimated value of 3,336,206 tonC and R-square value(0.35 and 0.18 respectively) is higher than that of when all sample plots used. The result of leave-one-out cross validation of each method indicates that RK with all sample plots reached the smallest root mean square error(RMSE) value(22.32 ton/ha) but the difference between the methods(0.23 ton/ha) is not significant.

• The Korean Journal of Applied Statistics
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• v.32 no.4
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• pp.607-618
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• 2019

A new and interesting task in statistics is to effectively analyze functional data that frequently comes from advances in modern science and technology in areas such as meteorology and biomedical sciences. Functional linear regression with scalar response is a popular functional data analysis technique and it is often a common problem to determine a functional association if a functional predictor variable affects the scalar response in the models. Recently, Kong et al. (Journal of Nonparametric Statistics, 28, 813-838, 2016) established classical testing methods for this based on functional principal component analysis (of the functional predictor), that is, the resulting eigenfunctions (as a basis). However, the eigenbasis functions are not generally suitable for regression purpose because they are only concerned with the variability of the functional predictor, not the functional association of interest in testing problems. Additionally, eigenfunctions are to be estimated from data so that estimation errors might be involved in the performance of testing procedures. To circumvent these issues, we propose a testing method based on fixed basis such as B-splines and show that it works well via simulations. It is also illustrated via simulated and real data examples that the proposed testing method provides more effective and intuitive results due to the localization properties of B-splines.

• Journal of Gifted/Talented Education
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• v.22 no.4
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• pp.875-892
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• 2012

The purpose of this study was to investigate the relationship among peer relation disposition, relationship maintenance effort and school adjustment of gifted students and non-gifted students. And then the final purpose of the study is to give suggestions to help improving gifted students' peer relationship and their school adjustment. For the study, 175 gifted students and 179 non-gifted students in grades 4 and 6 of 5 elementary schools in urban areas were assessed on their peer relation disposition, relationship maintenance effort and school adjustment. The results are summarized as follows. First, gifted students were significantly higher than that of the non-gifted students as a whole. Second, in the correlation among peer relation disposition, relationship maintenance effort and school adjustment, peer relation disposition and relationship maintenance effort showed a significantly positive correlation with all the subvariables of school adjustment. Third, Sympathy-Acceptance disposition was the most influential factor for gifted students, and Independence-Responsibility disposition was the most influential factor for non-gifted students. Finally, the cluster analysis results based on the peer relation type of the gifted and the non-gifted suggested four meaningful clusters. And the four clusters showed significantly differences with all the subvariables of school adjustment. Implications of the study were discussed in depth related to the gifted education practices.

• The Korean Journal of Applied Statistics
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• v.27 no.7
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• pp.1125-1137
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• 2014

This paper studies what affects the private education cost for the elementary, middle, and high school students. It is a big issue now because there can be a problem in the equal opportunity for education if the portion of private education cost is very high in the total education cost. If we spend more time and money on the private education than the school education, it can cause the polarization among the classes and regions. The excessive private education also can deteriorate the school system. we use various regression and classification methods to analyze the cost of private education and find the important variables in the models. we found that large cities spend more money on the private education than small cities. We also found that high school students spend more than middle school students and the elementary students and the household with more income spend more money on the private education.

• International Journal of Highway Engineering
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• v.10 no.3
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• pp.47-56
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• 2008

Generally, accident exposure at intersections is relatively higher than that at roadway segments due to more possibility of merging, diverging, turning, crossing, and weaving maneuver. Furthermore, the traffic accident rate at intersections has been rapidly increasing since 1990's. Since there is more opportunity of conflict at unsignalized intersection, frequency and severity of traffic accident are more severe than signalized intersections. The purpose of the study is to analyze factors causing vehicle crashes and provide intersection design guidelines to improve intersection safety. For this study, vehicle to vehicle crash data of 116 rural 3 legs unsignalized were collected and field surveys were conducted for traffic and geometric conditions. Ordered probit models were developed to analyze the severity of crashes. It was found that weather, obstacles in minor roadsides, presence of major exclusive right lane, presence of major road crosswalk, difference between posted speed of major road and minor road, land-use around intersections, shoulder width of major road, ADT of major road are significant factors for intersection safety.

• Journal of the Korean Data and Information Science Society
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• v.28 no.4
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• pp.721-731
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• 2017

In this study, principal component analysis methods using Lasso penalty are introduced. There are two popular methods that apply Lasso penalty to principal component analysis. The first method is to find an optimal vector of linear combination as the regression coefficient vector of regressing for each principal component on the original data matrix with Lasso penalty (elastic net penalty in general). The second method is to find an optimal vector of linear combination by minimizing the residual matrix obtained from approximating the original matrix by the singular value decomposition with Lasso penalty. In this study, we have reviewed two methods of principal components using Lasso penalty in detail, and shown that these methods have an advantage especially in applying to data sets that have more variables than cases. Also, these methods are compared in an application to a real data set using R program. More specifically, these methods are applied to the crime data in Ahamad (1967), which has more variables than cases.