• 한국데이터정보과학회:학술대회논문집
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• 2003.05a
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• pp.135-144
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• 2003

A data set having missing observations is often completed by using imputed values. In this paper, performances and accuracy of five imputation procedures are evaluated when missing values exist only on the response variable in the exponential regression model. Our simulation results show that adjusted exponential regression imputation procedure can be well used to compensate for missing data, in particular, compared to other imputation procedures. An illustrative example using real data is provided.

• Journal of Information Technology Applications and Management
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• v.17 no.1
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• pp.35-54
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• 2010

Why does e-Learning service for individuals remain in the early development stage? To find the answers of this question, we adopted usefulness and intention to continued use as dependent variables based on technology acceptance model and inferred convenience, cost-effectiveness, social presence, interactivity, concentration, and procrastination as independent variables based on literature review and interview with e-Learning users. Convenience and cost-effectiveness of e-Learning tend to enhance usefulness and/or intention to continued use, while lack of social presence, interactivity, and concentration of e-Learning and academic procrastination tend to hinder usefulness and/or intention to continued use. To prove this research model, we used a data set collected from the survey. The respondents of survey were the undergraduate students who used voluntarily e-Learning. Data analysis was conducted using 275 respondents by partial least square. The analysis result of causal relation indicated that convenience and cost-effectiveness influenced both usefulness and intention to continued use, and that cost-effectiveness and concentration influenced only intention to continued use. But, interactivity and procrastination did not influence usefulness and intention to continued use.

• Journal of Korean Elementary Science Education
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• v.31 no.3
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• pp.358-371
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• 2012

The main purpose of this study was to examine elementary teachers' visual attention that appears in science textbook tables. This paper proposed that teachers' cognitive effectiveness can be different by the presence or absence of the title of tables. The eye fixation data of participants are collected by the eye tracker apparatus. Participants in this study were 10 elementary school teachers and the table on the 2007 revised science textbooks were selected as experimental stimuli. Information about eye-fixations are recorded when subjects are given 4 tables by eye tracker. Eye-fixation time as well as the ratio and the number of fixation can be obtained by using the eye tracker but also we can acquire a significant conclusion through these outcomes. As the result of the experiment, it took less time to interpret in the presence of the title than in the absence of it. However, this result is only effective only for the interpretation of simple stimulus; the presence of title does not influence on fixation time in the analysis of complicated stimulation. This study showed that it is better to insult the title in the tables because it helps teachers to recognize contents of the tables effectively.

• The Journal of the Korea Contents Association
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• v.22 no.6
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• pp.223-237
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• 2022

The purpose of this study is to examine the influence of the presence and transportation of the experience of seeing a musical upon satisfaction and verify the mediating effect of emotional responses. For this study, the researcher surveyed the audiences of a musical and analyzed the response from 339 participants. The data were analyzed using SPSS 23.0 and AMOS 23.0 programs. The findings of this study are as follows; First, the presence and transportation of the experience of seeing a musical had a significant impact on emotional responses. Second, the presence and transportation in the experience of seeing a musical had a significant impact on satisfaction. Third, the emotional responses to the musical had a significant impact on satisfaction. Fourth, emotional responses were shown to have a mediating effect in the relationship between the presence and transportation of the experience and the satisfaction with it. As the share of online performances in performing art industries is increasing and the paradigm of seeing a performance is changing, this study implies that it provided a set of basic data for the industry and producers of such events, who are now seeking a new profit model through not only in-person events but also online performances in the future.

• The Research Journal of the Costume Culture
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• v.32 no.4
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• pp.453-467
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• 2024

The Metaverse's virtual world is used in various industries and is expected to continue to grow in the future. In addition, the Metaverse is a new type of society that integrates various new technologies, and NFT products play an essential role. Therefore, NFT product characteristics and industry trends should be assessed to revitalize the NFT market. To this end, this study confirms the influence relationship between social presence and NFT product characteristics in the Metaverse environment and examines the impact of each characteristic on consumer satisfaction and continued engagement intention to NFT product. Statistical analysis such as exploratory factor analysis, reliability analysis, confirmatory factor analysis, correlation analysis, and structural equation modeling (SEM) using IBM SPSS Amos was conducted on data collected through a survey targeting male and female Korean consumers in their age group 10 to 50. Study results indicate that social presence significantly impacted all characteristics of NFT products (authenticity, scarcity, rarity, collectability, and interactivity). Scarcity and authenticity significantly impacted consumer satisfaction, and both authenticity and consumer satisfaction significantly impacted continued engagement intention. Thus, effective product development and marketing strategies can be established only by presenting different emphasized characteristics depending on the type of NFT product and the Metaverse's social presence.

• Journal of Families and Better Life
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• v.18 no.1
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• pp.153-166
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• 2000

The relations between friendships peer aggression and victimization by peers were examined with a sample of 426 second-grade junior high school students(210 boys and 216 girls) Data were collected using questionnaires regarding friendship(number of friends and presence of a best friend) peer aggression and victimization by peers. The number of friends was significantly related to peer aggression both in boys and girls indicating that the more friends they had the less peer aggression they showed. Peer aggression didn't vary as a function of the presence of a best friend. The number of friends was also significantly related to victimization both in boys and girls. The more friends they had the less victimization they experienced. Victimization varied as a function of the presence of a best friend only in adolescent boys in which those having a best friend were rated by peers to experience less victimization, Victimization was related to peer aggression both in boys and girls. T e more victimization they experienced the more peer aggression they showed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.729-733
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• 2003

The presence of local features within clusters incurred by multi-modal nature of data prohibits many conventional clustering techniques from working properly. Especially, the clustering of datasets with non-Gaussian distributions within a cluster can be problematic when the technique with implicit assumption of Gaussian distribution is used. Current study proposes a simple tandem clustering method composed of k-means type algorithm and hierarchical method to solve such problems. The multi-modal dataset is first divided into many small pre-clusters by k-means or fuzzy k-means algorithm. The pre-clusters found from the first step are to be clustered again using agglomerative hierarchical clustering method with Kullback- Leibler divergence as the measure of dissimilarity. This method is not only effective at extracting the multi-modal clusters but also fast and easy in terms of computation complexity and relatively robust at the presence of outliers. The performance of the proposed method was evaluated on three generated datasets and six sets of publicly known real world data.

• Proceedings of the Korean Statistical Society Conference
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• 2001.11a
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• pp.143-148
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• 2001

A dataset having missing observations is often completed by using imputed values. In this paper the performances and accuracy of complete case methods and four imputation procedures are evaluated when missing values exist only on the response variables in the Weibull regression model. Our simulation results show that compared to other imputation procedures, in particular, hotdeck and Weibull regression imputation procedure can be well used to compensate for missing data. In addition an illustrative real data is given.

• International Journal of Highway Engineering
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• v.19 no.5
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• pp.143-151
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• 2017

PURPOSES : The purpose of this study is to develop models of accidents occurring at circular intersections related to the time of day and night and driver gender, and to provide countermeasures for safer circular intersections. METHODS : Seventy intersections built before 2008 were surveyed for inclusion in the modeling. Traffic accident data from 2008 to 2014 were collected from the TAAS data set of the Road Traffic Authority. Sixteen variables explaining the accidents including geometry and traffic volume were selected from the literature and seven multiple linear regression models were developed using SPSS 20.0. RESULTS : First, the null hypotheses, that the number of traffic accidents are not related to driver gender or time of day, were rejected at a 5% level of significance. Second, seven statistically significant accident models with $R^2$ value of 0.643-0.890 were developed. Third, in daytime models by gender, when the right-turn-only lane was selected as the common variable, the number of lanes, presence of driveways and speed humps, diagrammatic exit destination sign, and total entering traffic volume were evaluated as specific variables. Finally, in nighttime models by gender, when the diagrammatic exit destination sign was selected as the common variable, total entering traffic volume, presence of right-turn-only lanes, number of circulatory road way lanes, and presence of splitter islands and driveways were identified as specific variables. CONCLUSIONS:This study developed seven accident models and analyzed the common and specific variables by time of day and gender. The results suggest approaches to providing countermeasures for safer circular intersections.

• Journal of Digital Convergence
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• v.17 no.12
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• pp.1-11
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• 2019

The purpose of this study is to investigate factors influencing educational performance and mediating effects of learning presence in the university flipped learning classroom. For achieving this purpose, self-regulation, learning presence, and collaborative preference were selected as learner variables, and perceived academic achievement and learning engagement were selected as variables for educational performance. To investigate causal relationships among the variables, 39 university students who took 16 week course flipped-learning class participated self-reported survey. Collected data were analyzed by multiple regression and mediation analyses. The results were as follows: first, learning presence and self-regulation affected learning engagement, and moreover, the learning presence mediated between self-regulation and learning engagement. Second, only learning presence affected perceived academic achievement. Therefore, various strategies for effective flipped learning should be considered, and well-designed classroom activities that can promote learners self-regulation, learning presence, and learning engagement are needed to successful flipped learning.