• Journal of KIISE:Software and Applications
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• v.34 no.12
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• pp.1045-1055
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• 2007

Latent topic models are statistical models which automatically captures salient patterns or correlation among features underlying a data collection in a probabilistic way. They are gaining an increased popularity as an effective tool in the application of automatic semantic feature extraction from text corpus, multimedia data analysis including image data, and bioinformatics. Among the important issues for the effectiveness in the application of latent topic models to the massive data set is the efficient learning of the model. The paper proposes an accelerated learning technique for PLSA model, one of the popular latent topic models, by an incremental EM algorithm instead of conventional EM algorithm. The incremental EM algorithm can be characterized by the employment of a series of partial E-steps that are performed on the corresponding subsets of the entire data collection, unlike in the conventional EM algorithm where one batch E-step is done for the whole data set. By the replacement of a single batch E-M step with a series of partial E-steps and M-steps, the inference result for the previous data subset can be directly reflected to the next inference process, which can enhance the learning speed for the entire data set. The algorithm is advantageous also in that it is guaranteed to converge to a local maximum solution and can be easily implemented just with slight modification of the existing algorithm based on the conventional EM. We present the basic application of the incremental EM algorithm to the learning of PLSA and empirically evaluate the acceleration performance with several possible data partitioning methods for the practical application. The experimental results on a real-world news data set show that the proposed approach can accomplish a meaningful enhancement of the convergence rate in the learning of latent topic model. Additionally, we present an interesting result which supports a possible synergistic effect of the combination of incremental EM algorithm with parallel computing.

• The Journal of the Korea Contents Association
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• v.8 no.3
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• pp.156-172
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• 2008

The point of departure is the Popularity of the electronic games among the youth generation. This study attempts to make up a questionnaire containing the questions which are intended for the youth generation realistically and at the same time in a meaningful way pedagogically. Any researcher who wants to understand the youth culture at the present time is necessary to approach the youth generation in a positive attitude of learning, so asking the questions to the youth generation is as important as having the answers. That is to say, this paper is not a statistical analysis of the questionnaire, nor a empirical research of youth's reception of the electronic games. Now that the emphasis of the paper is located on the very way of approaching the youth generation concerning the electronic games, this study starts with the university students in the first place because they are in a more advantageous milieu for conversation in the classroom on the subject. To be sure, this study will be able to cover the whole area of primary, junior or senior high-school by way of some modifications. Conclusively, this paper aims at providing with practical ideas of teaching, which immediately can be appropriated into the classroom by the teachers in the actual field, and drawing attention to the potential educational contents of the cultural products. Furthermore, the questionnaire proposed in the paper is meant for the first step towards the aesthetics of the electronic games with a view to the game-imagination.

• The Journal of the Korea Contents Association
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• v.18 no.8
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• pp.392-407
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• 2018

This study aims to prove the mediating effect of emotion dysregulation and perceived social support in the relationship between covert narcissism on the relation addiction. The researchers surveyed college students for about 3 weeks through a questionnaire on college campus or with the help of their colleagues and professors. The subjects were 362 students. SPSS, AMOS and Mplus were used for statistical analysis, correlation analysis and structural equation analysis. The conclusions are as follows : First, emotion dysregulation, relation addiction and covert narcissism showed positive correlation and covert narcissism, emotion dysregulation, relation addiction and perceived social support showed a significant negative correlation. Second, it was found that after investigating the mediation effect of emotion dysregulation and perceived social support in the influence between covert narcissism and relation addiction, emotion dysregulation turned out to have a significant mediating effect while perceived social support did not. Third, dual mediating effect was significant in emotion dysregulation and perceived social support in the influence between covert narcissism and relation addiction. These findings proved that covert narcissism, emotion dysregulation, perceived social support are variables that effect relation addiction, and also clarified that emotion dysregulation is a strong mediating variable in the influence between covert narcissism and relation addiction. Finally, when counseling a client with the same tendency as covert narcissism, it gives an opportunity to be aware of the emotional problem and an opportunity to positively perceive its own social resources, so as not to reach interpersonal problems such as relationship addiction pointed out the need for an approach.

• Journal of the Korean association of regional geographers
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• v.15 no.4
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• pp.510-523
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• 2009

Geodemographics(GD) can be defined as an analytical approach of socio-economic and behavioral data about people to investigate geographical patterns. GD is based on the assumptions that demographical and behavioral characteristics of people who live in the same neighborhood are similar and then the neighborhoods can be categorized with spatial classifications with the geographical classifications. Thus, this paper, in order to identify the applicability of the geographical classification of the GD, explores the concepts of the geodemographics into Seoul city areas with Korea census data sets that contain key characteristics of demographic profiles in the area. Then, this paper attempt to explain each area classification profile by using clustering techniques with Ward's and k-means statistical methods. For this as as as, this paper employs 2005 Census dataset released by Korea National Statistics Office and the neighborhood unit is based on Dong level, the smallest administrative boundary unit in Korea. After selecting and standardizing variables, several areas are categorized by the cluster techniques into 13, this paps as distinctive cluster profiles. These cluster profiles are used to cthite a short description and expand on the cluster names. Finally, the results of the classification propose a reasonable judgement for target area types which benefits for the people who make a spatial decision for their spatial problem-solving.

• Journal of Distribution Science
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• v.12 no.11
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• pp.45-53
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• 2014

Purpose - Goal setting is effective in any domain in which an individual or group has some control over the outcomes. It applies not only to work tasks but also to sports and health, and in various other settings. Its success depends on considering the mediators and moderators determining its efficacy and applicability. This study investigates the individual factors influencing academic goal attainability. Unlike previous studies, we focused on the effect of the relationships between individual traits (passion, tenacity, self-control) and specific motivation (vision, self-efficacy, implementation intentions) with academic goal attainability, rather than the effects of the relationship between commitment and the goal shielding mechanism with goal attainability. Research design, data, and methodology - Data collected through questionnaires were analyzed by the SPSS program. A total of 293 school students, who participated in the TOEIC program, participated in the survey. Slightly more than half were female (male: n=145 vs. female: n=148). We verified nine hypotheses through various statistical methods (reliability analysis, exploratory factor analysis, confirmatory factor analysis, structural equation model for the hypothesis test, bootstrapping test for the mediation test). Results - Data was analyzed in three phases. The first phase involved measurement analysis (i.e., item purification and factor structure confirmation), involving the scales of the three variables of individual traits, three mechanism variables, and goal attainability. The second phase involved estimating the proposed structural relationships among the key constructs (see Figure 1), using the results to test H1 to H9. The final phase involved examining the mediating effects of the three variables (vision, implementation intention, and self-efficacy). The research model shows that the independent variable passion has a significant result with both the mediators-vision and self-efficacy. Further, vision and self-efficacy significantly affect goal attainability. The second variable, self-control, shows a significant effect when mediated by implementation intentions, but the direct relationship between implementation intension and goal attainability shows an insignificant result. However, when further mediated by self-efficacy, it showed a significant effect between self-efficacy and goal attainability. Similarly, the third variable, tenacity, shows an insignificant result when mediated by vision. In contrast, the mediator self-efficacy shows a positive effect between tenacity and goal attainability. Conclusions - This study shows how these individual traits, when mediated with the appropriate motivational factors, resulted significantly in the attainability of academic goals. We may identify several theoretical and practical contributions. Theoretically, we developed a step further in the research into consumer goals and related studies. Future research could examine the effects of different learning goal types and their combinations with performance goals (e.g., learning goals first, then performance goals), different types of goal framing (approach success vs. avoid failure), the relation between goals and cognition (which, by implication, entails all of cognitive psychology), goal hierarchies, and macro goal studies with organizations of different sizes. More studies on the relationship between conscious and subconscious goals would also be valuable.

• The Korean Journal of Applied Statistics
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• v.30 no.3
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• pp.377-390
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• 2017

When conducting a survey, item nonresponse occurs if the respondent does not respond to some items. Since analysis based only on completely observed data may cause biased results, imputation is often conducted to analyze data in its complete form. The panel study is a survey method that examines changes of responses over time. In panel studies, there has been a preference for using information from response values of previous waves when the imputation of item nonresponses is performed; however, limited research has been conducted to support this preference. Therefore, this study compares the performance of imputation methods according to whether or not information from previous waves is utilized in the panel study. Among imputation methods that utilize information from previous responses, we consider ratio imputation, imputation based on the linear mixed model, and imputation based on the Bayesian linear mixed model approach. We compare the results from these methods against the results of methods that do not use information from previous responses, such as mean imputation and hot deck imputation. Simulation results show that imputation based on the Bayesian linear mixed model performs best and yields small biases and high coverage rates of the 95% confidence interval even at higher nonresponse rates.

• Journal of Korean Society of Steel Construction
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• v.13 no.5
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• pp.567-575
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• 2001

In order to consider statistical properties of probability variables used in the structural analysis the conventional approach using the safety factor based on past experience usually estimated the safety of a structure Also the real structures could only be analyzed with the error in estimation of loads material characters and the dimensions of the members. But the errors should be considered systematically in the structural analysis Safety of structure could not precisely be appraised by the traditional structural design concept Recently new aproach based on the probability concept has been applied to the assessment of structural safety using the reliability concept Thus the computer program by the Probabilitstic FEM is developed by incorporating the probabilistic concept into the conventional FEM method. This paper estimated for the reliability of a plane stress structure by Advanced First-Order Second Moment method using von Mises, Tresca and Mohr-Coulomb failure criterions. Verification of the reliability index and failure probability of attained by the Monte Carlo Simulation method with the von Mises criterion were same as PFEM, but the Monte Carlo Simulation were very time-consuming. The variance of member thickness and load could influence the reliability and failure probability most sensitively among the design variables from the results of the parameter analysis. The proper failure criterion according to characteristic of materials must be used for safe design.

• Journal of Wetlands Research
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• v.18 no.2
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• pp.173-182
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• 2016

Although the ecosystem extends numerous functions for the benefit of humankind, construction of horticultural facilities can potentially lead to the degeneration of some of these functions owing to the expansion of impervious regions and loss of habitats. Thus, this study aimed to examine the effect of construction of horticultural facilities on plant biodiversity. Analysis of the vegetation distribution characteristics showed that horticultural facilities had significantly lower plant diversity than did rice paddies. Hence, the proposed approach involved low-impact development, arrangement of habitat space, plant preservation, restricted use of chemical fertilizer, habitat creation, and reduced preservation cost. Lifestyle analysis suggested the importance of developing favorable environments for the growth of annual plants and aquatic plants. In all, 20 species of naturalized plants belonging to 10 families were identified. Furthermore, the proportion of these naturalized plants was higher in glass greenhouses and multi-span greenhouses, suggesting the advantages of employing natural soil mulching while avoiding concrete mulching. Statistical analysis was performed to validate the results, which suggested that impervious regions be converted to natural soils. Collectively, the findings of this study are expected to be used for establishing policies for the construction of eco-friendly and ecological horticultural facilities; this may aid the maintenance of sustainable agricultural landscapes and large-scale development of the reclaimed lands.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.1
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• pp.31-39
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• 2001

The purpose of this study is to reveal the factors leading to the problem of unilateral condylar fractures and suggest a treatment guideline of treatment for good prognosis in surgical treatment. The factors can be age, sex, fracture site, degree of displacement, posterior occlusion loss, post-operative alteration of condylar head position, post-operative condylar head resorption, and maxillomandibular fixation period. One hundred and eleven patients with unilateral condylar fractures, who were treated by surgical method from 1990 Feb. to 2000 Feb., were studied. Minimum follow-up period was 6 months. The results were as follows ; 1. In the age group of $41{\sim}60$, females had significantly higher complication rate than males, therefore we must be careful about treatment of female in this age group 2. In level I fractures of the mandibular condyle, because there were abundant complications when the patients were treated with fragment removal, conservative treatment is recommended over the surgical approach. 3. There were no differences in the complication rate, in the level II, III fractures. but were severe complications in the cases of patients treated by Dr.Nam's method or fragment removal. Therefore, open reduction and internal fixation is recommended over Dr.Nam's method or fragment removal. 4. In level IV fractures, open reduction and internal fixation is recommended 5. Although there was a higher complication rate depending on the degree of deviation, there was no correlation between the degree of deviation and development of complications in each level of fracture 6. Because the complication rate was higher in cases of condylar resorption, vertical dimension loss, and alteration of condylar head position, we must make an effort to prevent such complications during treatment

• Korean Journal of Childcare and Education
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• v.9 no.2
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• pp.239-262
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• 2013

The purpose of this study was to examine the types of image that early childhood teachers have about nursery teachers in detail in an effort to provide some information on how to build an ideal image of a nursery teacher. Another goal was to determine the right directions for teacher education based on the subjective opinions of early childhood teachers, which has not been covered in earlier studies. The Q-methodology was utilized to determine the awareness of early childhood teachers about the types of the images of nursery teachers and each type's characteristics. A Q-population was constituted by 310 types of images based on the results of earlier studies about the images of nursery teachers, and 48 Q-samples were selected according to frequency. And then 20 nursery teachers and 20 kindergarten teachers were asked to classify the images of nursery teachers in nine stages by using the Q-sort, and the data were analyzed by the statistical package PASW 18.0. As a result, four different types of images appeared that the early childhood teachers had about nursery teachers, and the images were respectively named 'a practical-teaching-oriented type of teacher', 'a negative-system critical type of teacher', 'a positive-humanistic type of teacher' and 'a neutral-emotionally type of teacher'.