• Journal of the Korea Society for Simulation
• /
• v.24 no.4
• /
• pp.89-96
• /
• 2015

The mediation methods suggested by Baron and Kenny, Sobel, Aroian and Goodman, have widely used to test the mediating effect. However, as there are many problems in statistical test power, as well as statistical accuracy, a bootstrapping technique has been suggested as an alternative. In this paper, we adopt the phantom variables based on the bootstrapping technique to test the mediating effect in multiple mediator model consisting of three or more mediating variables. In particular, we formulate the multiple mediator model for analyzing the relations among organizational resources, the absorption capacity as mediating variables and technology commercialization capabilities. And using the bootstrapping approach, we analyzed the mediating effect of the absorption capacity by setting of phantom variables and calculated total indirect effect size and the statistical significance. The empirical results are as follows. First, we confirmed that the bootstrapping approach and the phantom variable is the very efficient and systematic mediation method. Second, we recognized that there is a difference in the mediating characteristics of the absorption capacity depending on the resource characteristics of human resources and material resources obviously.

• Human Ecology Research
• /
• v.58 no.4
• /
• pp.483-496
• /
• 2020

This study examined the effects of eating alone, meal type, and dietary lifestyles on healthy eating capability of one-person households. We analyzed the mediation effects of weekly frequencies of each meal type taken by one-person households between eating habits such as eating alone and dietary lifestyles of one-person households and healthy eating capability. We also analyzed data from the 2019 Food Consumption Behavior Survey using a sample of 688 one-person households. Factor analysis, latent profile analysis, structural equation model analysis was conducted; direct and indirect effects of independent variables were tested using bootstrap method. The major results were as follows. Frequency of eating alone was about 10 times a week on average; one-person households had home-made meals about 12 times a week, for restaurant meals, 4 times, for delivered/take-out food, 0.39 times, and for other types, 0.44 times. Weekly frequencies of eating alone and meal types taken by one-person households were significantly different among the different socio-demographic groups. Dietary lifestyle was classified into four classes: traditional, health ignorant, food lifestyle ignorant, and balanced. Eating alone and dietary lifestyle had a significant effect on weekly frequency of each meal type. Frequencies of eating alone, balanced dietary lifestyle, and taking home-made meals had a positive direct effect on healthy eating capability, and frequency of taking delivered or take-out food and food consumption ignorant lifestyle had a negative direct effect. Eating alone, balanced and traditional dietary lifestyles had a positive indirect effect through the meal type; however, watching Mug-bang had a negative indirect effect.

• Journal of Korean Society of Rural Planning
• /
• v.26 no.4
• /
• pp.117-129
• /
• 2020

The purpose of this study is to verify the effect of the authentic leadership of social enterprise leaders on the happiness and job crafting of employees, the mediation effect of job crafting in the authentic leadership of the leader and the happiness of the employees, and the coordination effect by the Grit of the employees. For verification, the relationship between authentic leadership and job crafting, happiness and grit and seven research theories were established. In addition, 47 questionnaires were drawn through prior research on happiness, authentic leadership, job crafting, and grit, and five executives and workers of social enterprises in Chungcheongbuk-do(Province) were surveyed on a five-point Likert scale. The collected survey data were conducted through the SPSS and AMOS for basic statistical analysis. The Macro Process of the bootstrap method was used to verify the mediation effects, the regulated effects. This study has conducted exploratory and confirmatory factor analysis, correlation analysis, structural model analysis through the survey results and the analysis results verify the hypothesizes. The study found that authentic leadership affects the happiness and job crafting of employees, and that job crafting affects the happiness of employees, and the relationship between authentic leaders and employees affects job crafting. It has also been shown that the Grit of its employees affects their job crafting and happiness and also has a mediation effect on job crafting and happiness. In the policy environment of the changing rural development project, the social economy establishment plan for the virtuous circle of resources in the region should be considered, and education programs should be introduced to improve the authentic leadership of the leaders.

• Asia Marketing Journal
• /
• v.17 no.4
• /
• pp.21-42
• /
• 2016

Purpose: Social influence has a decisive role in shaping a person's cognition and behavior. Chinese face consciousness, including moral component, is an important part of Chinese traditional culture, which influences people to implement moral behavior. With both eye-tracking technology and traditional questionnaire, this research aims to explore people's moral psychology and the psychological processing mechanisms of Chinese face consciousness, as well as the impact of Chinese face consciousness on the preference for the ecological product. Method and Data: 75 college and MBA students' eye movement data were collected when they read different kinds of moral materials, as well as data from the subsequent questionnaires. To test the hypothesis, ANOVA analysis and Heat Map analysis were performed. Besides, the PROCESS of bootstrap was used to test mediation effect. Findings: The results reveal that: 1. Compared to the moral-situation reading, when subjects read immoral situations, they need more processing time due to the moral dissonance and cognitive load. 2. Compared to the control condition, when threatened moral self is primed, subjects prefer to choose ecological product. 3. Protective face orientation is the mediator between threatened moral self and preference to ecological product. Key Contributions: First, this study broadens the use of eye-tracking technology in marketing and demonstrates a better understanding of the relationship between morality and consumer behavior in a more scientific way. Second, this study not only distinguishes the meanings between "protective face orientation" and "acquisitive face orientation", but also innovatively validates that when moral self is threatened, consumers tend to choose ecological product as moral compensation in order to protect their face. It can shed light on the promotion of ecological product in practical applications.

• Journal of Korean Society for Quality Management
• /
• v.51 no.1
• /
• pp.67-78
• /
• 2023

Purpose: The purpose of this study is to investigate the COVID-19 pandemic-driven effect changes of quality factors on customer satisfaction in Korean Police Civil Affairs Service. Methods: This study fitted a regression model to the data collected by Korean National Police Agency from 2019 (before COVID-19 pandemic) to 2020 (during COVID-19 pandemic). In order to simultaneously estimate the effects of major seven quality factors on customer satisfaction for 'before the pandemic' and for 'during the pandemic', the regression model included not only customer satisfaction as the dependent variable, but also the fourteen independent variables consisting of the seven quality factors and their seven interaction terms. The interaction terms were defined by multiplying each quality factor by a dummy variable indicating either before or during the pandemic. Therefore, the coefficient estimates of the interaction terms indicate the changes of their corresponding quality factor effects on customer satisfaction between before and during the pandemic. The double bootstrap method was applied to test the significance of coefficient estimates. Results: Both before and during the pandemic, all quality factors had positive effects on customer satisfaction. However, these effects changed differently from before to during the pandemic: (increased) supportability, sincerity, and convenience; (decreased) integrity, professionalism, and fairness; (unchanged) promptness. Conclusion: This study found that the pandemic caused significant effect changes of quality factors on customer satisfaction in Korean Police Civil Affairs Service. This finding suggests the necessity of carefully monitoring such effect changes to effectively and efficiently improve customer satisfaction. This study also identified that from before to during the pandemic, supportability, sincerity, and convenience become more important and hence, need to be better managed.

• Journal of Industrial Convergence
• /
• v.21 no.5
• /
• pp.97-107
• /
• 2023

The purpose of this study was to provide basic data to improve happiness by verifying the mediating effect of career decision in the relationship between civic consciousness, community consciousness, career decision, and happiness of middle school students. As for the analysis data, the "2020 Gen Z Teenage Values Survey" data surveyed by the Korea Youth Policy Institute was used. Among the survey subjects, 2,703 middle school students who met the purpose of this study were sampled and analyzed using the SPSS WIN 25.0 program. For the analysis method, frequency analysis, descriptive statistical analysis, correlation analysis, and PROCESS MACRO Model Number 4 were used to verify the mediating effect, and indirect effects and significance were analyzed by applying the Bootstrap technique. The results of the study showed, first, that middle school students' sense of citizenship and community had a positive effect on happiness. Second, in the relationship between civic consciousness and happiness, career decision had a partial mediating effect. Third, in the relationship between community consciousness and happiness, career decision had a partial mediating effect. In other words, it is meaningful in that it presented policy alternatives and practical programs to improve the happiness of middle school students.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.18 no.1
• /
• pp.79-91
• /
• 2022

In this study, the effects of self-efficacy, perceived usefulness, perceived ease of use, and depression on college students' academic persistence in the COVID-19 epidemic and the resulting non-face-to-face education situation were identified as mediating effects on learning satisfaction. In the second semester of 2020, a survey was conducted on students enrolled in a four-year university in Daegu and the data were statistically analyzed. The path coefficient was estimated by the Smart PLS bootstrap method and the significance of the path coefficient was verified. The Sobel Test was conducted to verify the mediating effect of academic continuity intention as a parameter. The research results can be summarized as follows. First, it was found that self-efficacy and perceived usefulness had a significant influence in the relationship with learning satisfaction. Second, the relationship between learning satisfaction and academic continuity intention was found to have a significant influence. Third, depression and ease of use did not show any significant influence in the relationship between learning satisfaction. Finally, a Sobel Test was conducted to verify the mediating effect of academic continuity intention with self-efficacy, usefulness, ease of use, and depression as independent variables and learning satisfaction as parameters. As a result of both regression analyses, it was found that β values decreased, and learning satisfaction had a mediating effect. As a result of this study, it is suggested that research to increase learner satisfaction and develop various contents to increase the effectiveness of education that can increase self-efficacy and perceived usefulness should be conducted in parallel. I think this study can be used as basic data in establishing measures to continue studying for college students in natural disaster situations or psychological crisis situations called COVID-19.

• KIPS Transactions on Software and Data Engineering
• /
• v.9 no.4
• /
• pp.129-136
• /
• 2020

PM2.5 which is a very tiny air particulate matter even smaller than PM10 has been issued in the environmental problem. Since PM2.5 can cause eye diseases or respiratory problems and infiltrate even deep blood vessels in the brain, it is important to predict PM2.5. However, it is difficult to predict PM2.5 because there is no clear explanation yet regarding the creation and the movement of PM2.5. Thus, prediction methods which not only predict PM2.5 accurately but also have the interpretability of the result are needed. To predict hourly PM2.5 of Seoul city, we propose a method using random forest with the adjusted bootstrap number from the time series ground data preprocessed on different sources. With this method, the prediction model can be trained uniformly on hourly information and the result has the interpretability. To evaluate the prediction performance, we conducted comparative experiments. As a result, the performance of the proposed method was superior against other models in all labels. Also, the proposed method showed the importance of the variables regarding the creation of PM2.5 and the effect of China.

• Journal of Intelligence and Information Systems
• /
• v.19 no.2
• /
• pp.39-54
• /
• 2013

Recent explosive increase of electronic commerce provides many advantageous purchase opportunities to customers. In this situation, customers who do not have enough knowledge about their purchases, may accept product recommendations. Product recommender systems automatically reflect user's preference and provide recommendation list to the users. Thus, product recommender system in online shopping store has been known as one of the most popular tools for one-to-one marketing. However, recommender systems which do not properly reflect user's preference cause user's disappointment and waste of time. In this study, we propose a novel recommender system which uses data mining and multi-model ensemble techniques to enhance the recommendation performance through reflecting the precise user's preference. The research data is collected from the real-world online shopping store, which deals products from famous art galleries and museums in Korea. The data initially contain 5759 transaction data, but finally remain 3167 transaction data after deletion of null data. In this study, we transform the categorical variables into dummy variables and exclude outlier data. The proposed model consists of two steps. The first step predicts customers who have high likelihood to purchase products in the online shopping store. In this step, we first use logistic regression, decision trees, and artificial neural networks to predict customers who have high likelihood to purchase products in each product group. We perform above data mining techniques using SAS E-Miner software. In this study, we partition datasets into two sets as modeling and validation sets for the logistic regression and decision trees. We also partition datasets into three sets as training, test, and validation sets for the artificial neural network model. The validation dataset is equal for the all experiments. Then we composite the results of each predictor using the multi-model ensemble techniques such as bagging and bumping. Bagging is the abbreviation of "Bootstrap Aggregation" and it composite outputs from several machine learning techniques for raising the performance and stability of prediction or classification. This technique is special form of the averaging method. Bumping is the abbreviation of "Bootstrap Umbrella of Model Parameter," and it only considers the model which has the lowest error value. The results show that bumping outperforms bagging and the other predictors except for "Poster" product group. For the "Poster" product group, artificial neural network model performs better than the other models. In the second step, we use the market basket analysis to extract association rules for co-purchased products. We can extract thirty one association rules according to values of Lift, Support, and Confidence measure. We set the minimum transaction frequency to support associations as 5%, maximum number of items in an association as 4, and minimum confidence for rule generation as 10%. This study also excludes the extracted association rules below 1 of lift value. We finally get fifteen association rules by excluding duplicate rules. Among the fifteen association rules, eleven rules contain association between products in "Office Supplies" product group, one rules include the association between "Office Supplies" and "Fashion" product groups, and other three rules contain association between "Office Supplies" and "Home Decoration" product groups. Finally, the proposed product recommender systems provides list of recommendations to the proper customers. We test the usability of the proposed system by using prototype and real-world transaction and profile data. For this end, we construct the prototype system by using the ASP, Java Script and Microsoft Access. In addition, we survey about user satisfaction for the recommended product list from the proposed system and the randomly selected product lists. The participants for the survey are 173 persons who use MSN Messenger, Daum Caf$\acute{e}$, and P2P services. We evaluate the user satisfaction using five-scale Likert measure. This study also performs "Paired Sample T-test" for the results of the survey. The results show that the proposed model outperforms the random selection model with 1% statistical significance level. It means that the users satisfied the recommended product list significantly. The results also show that the proposed system may be useful in real-world online shopping store.

• The Korean Journal of Mycology
• /
• v.27 no.3 s.90
• /
• pp.191-197
• /
• 1999

The phylogenetic position of Gliocladium and its related taxa were investigated, using the neighbor-joining method of the sequences from internal transcribed spacers (ITS1 and ITS2) and 5.8S ribosomal DNA (rDNA). It was focused especially on the generic concept by comparing with the related genera such as Trichoderma, Hypocrea, Verticillium, Penicillium and Talaromyces. Gliocladium species and its related genus were divided into three groups by the phylogenetic analysis using the neighbor-joining method. The first group includes Penicillium-like strains such as Penicillium, Tararomyces, Verticillium and one species of Gliocladium (G. cibotii JCM 9203 and JCM 9206). Especially, Gliocladium cibotii JCM 9203 is thought to be the similar species with Verticillium bulbillosum JCM 9214. Between these two species, Gliocladium cibotii and Verticillium bulbillosum, the intraspecies concept needs to examined with culture condition. and morphological properties. The second group includes two species Verticillium, Verticillium tricorpus and Verticillium albo-atrum which extracted from the GenBank database in NCBI (National Center for Biotechnology Information). Trichoderma-like strains, such as Trichoderma, Hypocrea and several species of Gliocladium are included in the third group. Also, Gliocladium penicillioides IFO 5869 and Gliocladium catenulatum ATCC 10523 formed the subgroup of Trichoderma-like strains. The species of Gliocladium were dispersed in Trichoderma-like and Penicillinum-like group, and only one species of Gliocladium cihotii used in our study was located in Penicillium-like genus group. The species of Verticillium appeared in all three groups and the species of Trichoderma formed the monophylogeny with Hypocrea (telemorph). Also, Gliocladium virens was grouped with Trichoderma harzianum with a high bootstrap value, supporting that Gliocladium virens is to be placed in Trichoderma. The results suggest that Gliocladium is polyphyletic, and is more Trichoderma-like than Penicillium-like.