• Journal of agriculture & life science
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• v.52 no.6
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• pp.155-162
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• 2018

This study attempts to analyze the consumers' preference on Korean Red Ginseng Tonic, which is an essential product to revitalize Korean ginseng industry, using choice experiment method. The attributes used in the choice experiment were the ginseng age, good agricultural products(GAP), sugar, and price. A total of 1,796 experiments were collected and the value of each preferred attributes was estimated using a multinomial logistic model. The result shows that the products made from six-year-old and GAP(Good Agriculture Practice) approved Korean ginseng with less sugar were preferred. These estimated monetary values of marginal willingness to pay were about 94,000 KRW, 89,000 KRW, 5,000 KRW, respectively. Thus, the efforts to introduce and advertize GAP approved ginseng while developing new products with preferred attributes by general publics are necessary in the short run. In addition, we may need to consider developing the way to promote products using 4- and 5-year-old ginsengs, which are relatively underestimated in their health effectiveness but highly productive for farmers in the long run.

• The Korean Journal of Applied Statistics
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• v.32 no.3
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• pp.349-374
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• 2019

A class imbalance problem arises when one class outnumbers the other class by a large proportion in binary data. Studies such as transforming the learning data have been conducted to solve this imbalance problem. In this study, we compared resampling methods among methods to deal with an imbalance in the classification problem. We sought to find a way to more effectively detect the minority class in the data. Through simulation, a total of 20 methods of over-sampling, under-sampling, and combined method of over- and under-sampling were compared. The logistic regression, support vector machine, and random forest models, which are commonly used in classification problems, were used as classifiers. The simulation results showed that the random under sampling (RUS) method had the highest sensitivity with an accuracy over 0.5. The next most sensitive method was an over-sampling adaptive synthetic sampling approach. This revealed that the RUS method was suitable for finding minority class values. The results of applying to some real data sets were similar to those of the simulation.

• The Journal of the Korea Contents Association
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• v.21 no.4
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• pp.278-291
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• 2021

This study performed a longitudinal research on the causal relationship between multidimensionality of problem drinking and poverty, and multidimensional deprivation meaning the inequality, focusing on gender difference. For this, this study examined the latent group of problem drinking change trajectory through the latent class growth analysis targeting total 3,770 men and 5,632 women by using the 6th-year Korea Welfare Panel Study data from 2013 to 2018, and then conducted the multinominal logistic regression analysis to verify the influence of multidimensional deprivation factors on this latent group. The main results of this study are as follows. First, the latent group of problem drinking change trajectory according to gender was classified into three latent groups in both men and women while the development aspect was different from each other. The male latent group with 'moderate level' or higher showed higher level of problem drinking than women. However, in case of 'drinking group with high level' according to gender, as time passed, the men tended to maintain it while the women tended to increase it. Second, in the results of examining the effects of multidimensional deprivation on the latent group of problem drinking change trajectory, the men with more experiences of social deprivation and the women with more experiences of social security deprivation showed the higher possibility to belong to the 'drinking group with high level' compared to the 'drinking group with low level'. Based on such results above, this study discussed the preventive/intervention measures for problem drinking according to gender.

• Journal of the Korean Regional Science Association
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• v.38 no.1
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• pp.45-56
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• 2022

The purpose of this study is to examine the differences among the income level groups of young single-person households and newlywed households in factors affecting the choice of residential location in the Seoul metropolitan region. To summarize the results of the analysis, first, there were differences in the factors affecting the choice of residential location by income level in both single-person young households and newlyweds. Second, among young households, the low-income group showed a behavior of choosing a residential location based on bounded rationality considering the economic condition of the household. Third, even though the income level is similar, the difference in the factors for choosing a residential location between single-person young households and newlywed households was confirmed, which is results of the life-cycle changes. These results imply that it is necessary to prepare appropriate housing policies that can supplement the economic conditions of young households living in the Seoul metropolitan region, and to review customized housing policies that reflect changes in life-cycle stages as well as age or income level.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.580-595
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• 2022

This study looked at the relationship between lifestyle choices and various substance addictions in young adults by applying the Relapse Prevention model of addiction. The data was obtained from a cross-sectional questionnaire (Depression and Anxiety Assessment Test) of 926 young adults aged 18~24 from 24 countries. Of these, 17.6% reported that they had a serious substance addiction, with alcohol addiction being the highest (11.2%), followed by nicotine (10.3%) and illicit drug (8.7%) usage. Results of chi-square test and logistic regression analysis revealed a significant association between various lifestyle factors (exercise patterns, intake of dietary nutrients like tryptophan, folic acid, omega-3 fatty acids and micronutrients, spiritual habits such as Bible reading and prayer) and addiction to various substances (illicit drugs, alcohol and nicotine). Depression was also found to be a significant factor influencing substance addiction. Interestingly, the risk of alcohol abuse was the highest at 9.870 (95% CI: 4.525-21.525) times among those who didn't have the habit of daily Bible reading. The highest risk of nicotine and illicit drug addiction was among those who consumed 'less than 1 serving' of dietary micronutrients per day compared to those who consumed '5 or more servings', with odds ratios of 9.606(95% CI: 2.726-30.111) and 8.642(95% CI: 2.022-37.378), respectively. These findings suggest that holistic lifestyle interventions may help prevent and reduce substance addiction in young adults.

• 한국노년학
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• v.40 no.1
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• pp.163-178
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• 2020

The purpose of this study is to analyze leisure factors affect happiness of the elderly by sex in Korea and then to discuss implications for the findings. Data of National Leisure Activity Survey conducted by Korea Culture & Tourism Institute in 2016 were used for this study. From this dataset, 891 male elderly and 970 female elderly aged above 65 were selected for this study. Ordered logistic regression model was used by considering the nature of the dependent variable. The results of this study can be summarized as follows. First, choice proportions of leisure activities classified by four type are different by sex of the elderly. Second, among control variables, household income, residential area, joining a club have different significant effect on happiness of the elderly by sex but volunteering have same significant effect on happiness of the elderly by sex. Third, any type of leisure activity have no significant effect on happiness of both the male elderly and the female elderly. Fourth, cost of leisure has significant positive effect on happiness of both the male elderly and the female elderly but has different significance by sex. Fifth, focus on leisure rather than work has very significant positive effect on happiness of both the male elderly and the female elderly. Sixth, leisure life satisfaction has very significant positive effect on happiness of both the male elderly and the female elderly.

• Journal of Industrial Convergence
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• v.20 no.2
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• pp.1-9
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• 2022

As the need for improvement of transparency and fairness in the selection of national R&D projects has been continuously raised, we analyzed the impact on the evaluation selection results by evaluation indexes for The land transportation technology commercialization support project and searched for ways to improve indexes using the analysis results. As for the research data, it were applied as selection results of new R&D projects and evaluation indexes in two fields(SME innovation and start-up) in 2021. Logistic regression analysis is used for the influence of each evaluation indexes on the evaluation result, and for the regression model, evaluation indexes with low influence are removed in advance through artificial neural network multiple perceptron analysis to improve the reliability of the analysis results. As a result of the analysis, in the field of SME innovation, the influence of the evaluation index on the workforce planning was the lowest and the influence of the appropriateness of commercialization promotion plan was the highest. In the start-up field, the influence of the evaluation indexes for technology development suitability, marketability, and suitability for carrying out the project were estimated to be similar to each other, and the influence of the technology evaluation index was found to be the lowest. The analysis results of this thesis suggest the need for continuous improvement of selection and evaluation indexes, and by using the analysis results to select a fair R&D institution according to the selection of appropriate indexes, it will be possible to contribute to deriving excellent research results and fostering excellent companies in the field of land transportation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.4
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• pp.115-124
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• 2022

Unlike the semi-public system of city buses, Seoul's townbus are operated on a private operating system, which is poor condition to the changes in the environment. Sales decreased due to a decrease in the number of passengers due to COVID-19 and a demand for conversion due to the advent of competitive transportation methods, and the financial support of Seoul Metropolitan Government is continuously increasing. In this study, to analyze the characteristics of townbus operated by a private operating system, the townbus sales and surplus companies were analyzed by what factors were affected. For the analysis data, townbus financial statements of Seoul in 2018 were used, and townbus sales and surplus companies were applied as dependent variables, and townbus operation system, satisfaction survey, humanities and social variables, and subway and public bicycle characteristics were applied as independent variables. As a result of the analysis, the sales is affected by operating hours per vehicle, in-vehicle safety, the number of households, the number of elderly people, and public bicycle variables, and surplus companies are affected by in-vehicle safety, reliability, and public bicycle variables. In particular, public bicycles, a competitive means of transportation, had an impact on industry sales, and the townbus business environment is expected to become more difficult as time goes by. The industry is seeking self-rescue measures, and Seoul is required to strengthen financial support so that townbus can operate stably.

• Journal of the Korean Society for Library and Information Science
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• v.56 no.3
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• pp.5-26
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• 2022

The purpose of this study is to analyze high school students' understanding and use of the recommended books lists. The survey distributed to high school students in seven high schools located in Seoul, and 311 students responded. Using SPSS 24, the data was analyzed by frequency, binary logistic model, and one-way ANOVA. Results show the followings. First, the meaningful factors affecting students' use of recommended books lists are gender, grade levels, and the degree to which students think recommended books lists include the books that are suitable and interesting. Particularly, the degree to which students think recommended books lists include the suitable books for them is the strong factor affecting students' use of the recommended books lists. Second, male students are less likely to use recommended books lists than female students. Male students consistently are less likely to use the recommended books lists made by school librarians, subject teachers, and reading experts and/or organizations. Third, teacher-librarians believed that the recommended books lists would help students who do not enjoy reading and have difficulties in reading. However, the study finds that students who enjoy reading and read well are more willing to use the recommended books lists made by school librarians, subjects teachers, and reading experts and/or organizations than those who do not. Fourth, students are most willing to use the recommended books lists for college preparation. The findings suggest the further research topics in designing the recommended books lists suitable for high school students and in scaffolding the high school students' use of book information reflected in recommended books lists.

• Journal of Industrial Convergence
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• v.20 no.12
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• pp.1-9
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• 2022

The objective of this study was to analyze the factors affecting the stages of change of exercise in middle-aged men who work. 170 middle-aged men who work surveyed, 40 to 59 years old, is residing, Chung-Buk and Chung-Nam province, who understand the purpose of this study and agree to participate in this study. This study data is analyzed by using frequency, percentage, standard deviation, t-test, 𝑥² test and Logistic regression analysis. The study show that the exercise self-efficacy(𝛽=.965, p=.003) and the perceived health status(𝛽=.805, p=.025) among middle aged men who work have an effect on the stages of change of exercise meaningfully. That is, the exercise self-efficacy of middle aged men who work who have exercise behavior is 2.6 times higher than middle aged men at work who don't have exercise behavior, and the perceived health status is 2.2 times higher. This study suggests that the development of better exercise practice for middle aged men who work should be aimed at promoting exercise self-efficacy and perceived health status, Based on this, it is necessary to find ways to operate exercise programs at the workplace and community level.