• Journal of the Korean Data and Information Science Society
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• v.22 no.4
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• pp.691-699
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• 2011

Land sliding is one of well-known nature disaster. As a part of effort to reduce damage from land sliding, many researchers worked on increasing prediction ability. However, because previous studies are conducted mostly by non-statisticians, previously proposed models were hardly statistically justifiable. In this paper, we predicted the probability of land sliding using the logistic regression model. Since most explanatory variables under consideration were correlated, we proposed the final model after backward elimination process.

• The Journal of the Korea Contents Association
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• v.14 no.11
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• pp.829-837
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• 2014

This study was conducted to investigate the factors that influence the psychosocial adaptation and quality of life of hemodialysis patients. The study participants consisted of 246 hemodialysis patients from 8 hemodialysis centers located in 3 cities ('K', 'P', and 'U') in South Korea. The questionnaire used for data collection was administered between April 1 and 30 of 2014. SPSS/WIN 18 program was used to perform descriptive, correlation, and stepwise regression analyses. It was found that stress response and acceptance were significantly correlated with psychosocial adaptation and quality of life. In the stepwise regression analysis, stress response appeared to be the most important influencing factor for psychosocial adaptation (${\beta}$=-.443, p<.001) and quality of life (${\beta}$=-.553, p<.001). Based on the study results, it is determined that in order to improve psychosocial adaptation and quality of life among hemodialysis patients, an intervention program to reduce stress response is needed, along with evaluating its efficacy.

• Journal of Navigation and Port Research
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• v.43 no.1
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• pp.72-78
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• 2019

The second-hand ship market provides immediate access to the freight market for shipping investors. When introducing second-hand vessels, the precise estimate of the price is crucial to the decision-making process because it directly affects the burden of capital cost to investors in the future. Previous studies on the second-hand market have mainly focused on the market efficiency. The number of papers on the estimation of second-hand vessel values is very limited. This study proposes an artificial neural network model that has not been attempted in previous studies. Six factors, freight, new-building price, orderbook, scrap price, age and vessel size, that affect the second-hand ship price were identified through literature review. The employed data is 366 real trading records of Panamax second-hand vessels reported to Clarkson between January 2016 and December 2018. Statistical filtering was carried out through correlation analysis and stepwise regression analysis, and three parameters, which are freight, age and size, were selected. Ten-fold cross validation was used to estimate the hyper-parameters of the artificial neural network model. The result of this study confirmed that the performance of the artificial neural network model is better than that of simple stepwise regression analysis. The application of the statistical verification process and artificial neural network model differentiates this paper from others. In addition, it is expected that a scientific model that satisfies both statistical rationality and accuracy of the results will make a contribution to real-life practices.

• Korean Journal of Environment and Ecology
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• v.34 no.1
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• pp.55-62
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• 2020

To estimate headwater stream temperature with seasonal variations, we analyzed precipitation, runoff and air temperature in experimental forest of Kangwon National University, Gangwon-do (2017~2018 years). The daily mean value of headwater stream temperature for spring was 6.9~17.7℃ and correlated with air temperature, that for summer and fall were 12.2~26.3℃ and 3.6~19.3℃, correlated with air temperature and runoff. Based on seasonal variations, we applied for stepwise multiple linear regression analyses to estimate headwater stream temperature with seasonal variations. The equations were headwater stream temperature(WT)_spring=(0.553×Air temperature)+(0.086×Runoff)+4.145 (R²=0.505; p<0.01), WT_summer=(0.756×Air temperature)+(-0.072×Runoff)+2.670 (R²=0.510; p<0.01), and WT_fall=(0.738×Air temperature)+(0.028×Precipitation)+2.660 (R²=0.844; p<0.01). The coefficient of determination (R²) was greater than when it was estimated by air temperature in all seasons and progressively increased from spring to winter. Therefore, we indicated difference on estimated magnitude of stepwise multiple linear regression, due to effects on headwater stream temperature of different environmental factors with seasonal variations. Furthermore, temporal factors with spatial characteristics (e.g., river versus headwater stream) could be recommended for estimating headwater stream temperature.

• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1133-1146
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• 2015

The Horse race industry has the largest proportion of the domestic legal gambling industry. However, there is limited statistical analysis on horse races versus other sports. We propose prediction models for winning horses in horse races using data mining techniques such as logistic regression, linear regression, and random forest. Horse races data are from the Korea Racing Authority and we use horse racing reports, information of racehorses, jockeys, and horse trainers. We consider two models based on ranks and time records. The analysis results show that prediction of ranks is affected by information on racehorses, number of wins of racehorses and jockeys. We place wagers for the last month of races based on our prediction models that produce serious profits.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.490-501
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• 2018

This study was conducted to develop and test effects of E-book based Flipped Learning education for nursing students. This study was one-group pretest-posttest design. The data were collected from 54 second-year nursing students in the located Y city and August 28 2017 to October 16 2017. The data were analyzed by descriptive statistics, paired t-test, Pearson's correlation coefficient, and stepwise multiple regression with SPSS 20.0 program. The results showed that the program was effective in increasing the critical thinking disposition (t=-8.62, p<.001), academic self-efficacy (t=-9.62, p<.001) and major satisfaction (t=-8.11, p<.001). The result of the stepwise multiple regression indicates the critical thinking disposition predict 13.4% (F=9.22, p<.001) of major satisfaction. The result of the stepwise multiple regression indicates the critical thinking disposition predict 13.4% (F=9.22, p<.001) of major satisfaction. Therefore, strategies for enhancing critical thinking disposition is needed by applying various teaching and learning strategies for nursing students.

• Journal of Korea Water Resources Association
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• v.55 no.4
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• pp.257-266
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• 2022

Inundation damage is increasing every year due to localized heavy rain and an increase of rainfall exceeding the design frequency. Accordingly, the importance of hydraulic structures for flood control and defense is also increasing. The hydraulic structures are designed according to its purpose and performance, and the amount of flood is an important calculation factor. However, in Korea, design rainfall is used as input data for hydrological analysis for the design of hydraulic structures due to the lack of sufficient data and the lack of reliability of observation data. Accurate probability rainfall and its temporal distribution are important factors to estimate the design rainfall. In practice, the regression equation of temporal distribution for the design rainfall is calculated using the cumulative rainfall percentage of Huff's quartile method. In addition, the 6^th order polynomial regression equation which shows high overall accuracy, is uniformly used. In this study, the optimized regression equation of temporal distribution is derived using the variable selection method according to the principle of parsimony in statistical modeling. The derived regression equation of temporal distribution is verified through the significance test. As a result of this study, it is most appropriate to derive the regression equation of temporal distribution using the stepwise selection method, which has the advantages of both forward selection and backward elimination.

• Korean Journal of Human Ecology
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• v.18 no.3
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• pp.705-717
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• 2009

본 연구의 목적은 미국 여대생의 자의식, 물질주의성향, 충동구매와 과시적 소비성향간의 관계에 관하여 조사하는데 있다. 상징적 자기완성이론을 이론적 근거로 하여 가설을 설계하였으며, 설문지 조사법을 이용하여 자료를 수집하였다. 편의표본추출법을 적용하여 미국 중서부지역의 한 대학교의 여대생 315명을 연구대상으로 설문조사를 하였으며, 최종적으로 296명의 응답을 연구결과분석에 이용하였다. Stepwise 회귀분석을 통한 분석 결과 공적 자의식은 물질주의성향과 충동구매성향 및 과시소비성향에 정적 영향을 미치는 것으로 나타났으며, 사적 자의식은 과시소비성향에 부적 영향을 미치는 것으로 나타났다. 또한, 단순회귀분석을 통한 분석 결과 물질주의성향과 충동구매성향 및 과시적 소비 성향 간에 정적인 관계가 있는 것으로 나타났다. 본 연구는 자의식, 물질주의성향, 충동구매와 과시소비 성향간의 관계 메커니즘을 증명해 보임으로써, 사회 심리학적 소비자 행동연구에 이론적 틀을 제시하였다. 또한, 본 연구결과는 미국 여대생을 표적 시장으로 하는 기업이 표적소비자의 소비행동과 심리를 이해하는데 중요한 자료로 이용될 것으로 기대된다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.4
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• pp.1619-1624
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• 2012

The purpose of this study is to examine the mental health of married immigrant women and the effect of cultural adaptation stress of married immigrant women on mental health. The subjects were 239 married immigrant women who live in Pusan city. Collected date were analyzed through frequency, percentage, and stepwise multiple regression analysis. The results are as follows. The 17.6% of the sample had the problem of mental health. The result of stepwise multiple regression analysis indicated that factors which predict the level of married immigrant women's mental health were cultural shock, fear, and guilty feeling. The findings give us significant practical implications for social work intervention.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.355-363
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• 2018

Found pesticide-contaminated eggs in 2017, the situation became a hot issue in many countries in the world as well as Korea. In the context of the pesticide-contaminated egg, this study explored that preventive behavioral intention would be predicted by perceived susceptibility and severity from health belief model, trust in the government and evaluation of information from the government, and subjective knowledge. We found that preventive behavioral intention was explained by perceived severity (${\beta}=.262$, t=3.531, p<0.001), trust in the government (${\beta}=.25$, t=3.281, p<0.001), and evaluation of the information from the government (${\beta}=.226$, t=2.936, p<0.01) through stepwise multiple linear regression analysis. The findings imply the government would administer policy in terms of credibility, accuracy, and consistency for decreasing the public's sense of unease and panic when a similar incident occurs.