• Communications of Mathematical Education
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• v.34 no.3
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• pp.325-354
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• 2020

This study utilized longitudinal data from the 2013 year (Secondary Middle School) to 2017 year (Secondary High School) of the Seoul Education Termination Study. Using the latent growth model and the piecewise growth model, we investigated the changes in mathematics academic achievement, internal factors(self-concept, self-control, self-assessment of life satisfaction), and external factors(school climate, guardians) as students' grades increased, and examined whether internal factors and external factors influence the changes in mathematics academic achievement. We examined whether internal and external factors influence the change in academic achievement. As a result of analysis, it was found that mathematics academic achievement remained unchanged from the first grade of middle school to the second grade of middle school, and steadily increased from the second grade of middle school to the first grade of high school, and then decreased slightly in the second grade of high school. The internal and external factors had little change. It has been found that self-concept, self-control as internal factors, and school climate as external factors influence changes in mathematics academic achievement.

• Journal of the Korean Association of Geographic Information Studies
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• v.5 no.3
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• pp.99-106
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• 2002

The application method of GIS for planning of forest road network can be save the efforts and cost by frequently change of forest road and evaluation the forest road route before construction. The purpose of this study is to suggest the proper method for planning an optimal forest road network in mountains forest using geographic information system(GIS) in the national forest of Mt. Kumsan at Namhae-gun, Gyungsangnam-do. In the forest road network planning by the minimum longitudinal gradient, The total length was 20.41km, and road density was 6.92m/ha. In the forest road network planning by mixed with the minimum longitudinal gradient and the maximization of investment effect, The total length was 21.15km, and road density was higher than that of the minimum longitudinal gradient as 7.17m/ha. The road length overlapped by cost path was more short than 3.52m/ha of the minimum longitudinal gradient as 1.73km. So, it appeared that forest road has an high effectiveness in yarding function. Therefore, it considered that the geographic information system could provide an effective and resonable solutions for planning of optimal forest road network.

• Journal of Internet Computing and Services
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• v.20 no.1
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• pp.17-24
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• 2019

Since the information of $4^{th}$ Industrial Revolution is introduced in WEF (World Economic Forum) in 2016, IoT, AI, Big Data, 5G, Cloud Computing, 3D/4DPrinting, Robotics, Nano Technology, and Bio Engineering have been rapidly developed as business applications as well as technologies themselves. Among the diverse business applications for IoT, wearable devices are recognized as the leading application devices for final customers. This longitudinal study is compared to the results of the 1st study conducted to identify customer needs of activity trackers, and links the identified users' needs with the well-known marketing frame of marketing mix. For this longitudinal study, a survey was applied to university students in June, 2018, and ANOVA were applied for major variables on usable features. Further, potential customer needs were identified and visualized by Word Cloud Technique. According to the analysis results, different from other high tech IT devices, activity trackers have diverse and unique potential needs. The results of this longitudinal study contribute primarily to understand usable features and their changes according to product maturity. It would provide some valuable implications in dynamic manner to activity tracker designers as well as researchers in this arena.

• Phonetics and Speech Sciences
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• v.13 no.4
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• pp.101-114
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• 2021

The purpose of this study was to investigate the temperament characteristics associated with stuttering subtypes (persistent and recovered) over time and the relationship between those characteristics and stuttering severity. This four-year longitudinal study covered 41 preschool children who stutter (CWS) and 30 preschool children who do not stutter (the CWNS group). At the final visit, 27 CWS were classified as the Recovered group and 14 CWS were classified as the Persistent group. Using the Children's Behavior Questionnaire-Short Form, each participant's temperament characteristics were measured twice: at one year and two years after the initial visit. The three subscale scores (Extraversion, Negative Affectivity, and Effortful Control) and the 15 component scores were analyzed, and they were used for between-group and between-visit comparisons. The Persistent group showed a significantly higher Negative Affectivity subscale score at every visit than the Recovered and CWNS groups. Within this subscale, significant group differences were found in the 'Fear' and 'Anger/Frustration' components, demonstrating that the Persistent group scored higher than the Recovered and CWNS groups. There was no significant correlation between the subscale and component scores and the stuttering severity scores within the Persistent group at any visit. These results support the proposition that these two stuttering subtypes have different temperament characteristics; they also imply that temperament might be influenced by stuttering experience over time.

• Korean Journal of Culture and Social Issue
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• v.13 no.1
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• pp.1-41
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• 2007

This study examines factors that influence delinquent behavior among Korean adolescents using longitudinal analysis. A total of 1,012 students completed a questionnaire when they were Grade 6 and 739 students completed a follow-up questionnaire when they became Grade 9. Results of multiple regression analysis indicate that the following variables predicted delinquent behavior of Grade 9 students: Bullying, previous delinquency, experience of punishment, victimization, social efficacy, and moral disengagement. The above six variables have direct and mediating influence of delinquent behavior. Relational factors also influenced delinquent behavior. Social exclusion from friends reduce social efficacy, which increases victimization and which in turn increases bullying, leading to greater delinquency. Parental rejection, social exclusion from friends and hostility from teachers increase moral disengagement, which increases bullying, leading to delinquency. Low academic achievement increases the likelihood of being punished, which increases bullying, leading to delinquency. The results indicate that moral disengagement and social efficacy are mediating factors of delinquency and negative life-events (i.e., social exclusion from friends, rejection from teachers, hostility from parents and low academic achievement) increase the likelihood that Korean adolescents will engage in delinquent behavior. Implications of the results for future research are discussed.

• Korean Journal of Social Welfare Studies
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• v.47 no.4
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• pp.309-332
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• 2016

This research attempts to calculate the vertical equity of National Health Insurance Contribution of locally provided policy holders by abilities to pay. Also, this longitudinal study examined the influence of abilities to pay and demographic characteristics on the health insurance premium. Using data from the Korea Welfare Panel Study, this study followed the self-employed households who continued to participate in the survey from 2011 to 2015. Kakwani's index of progressivity was measured as a measure of vertical equity and panel regression analysis was conducted by STATA program. The results of this research are as follows. First, from 2011 to 2015, the values of kakwani's index were negative according to composite income, which meant some levels of regressiveness of contribution. Secondly, panel regression analysis showed that the lowest household of composite income had a significantly negative effect on premiums, which also meant regressiveness. Based on the results, the author suggested political discussions on reorganizing the system of imposing the National Health Insurance contribution.

• Journal of the Korean Society for Library and Information Science
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• v.57 no.1
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• pp.45-68
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• 2023

The purpose of this study is to longitudinally analyze impact factors on library use. One of library use indicators, the number of circulated books was statistically analyzed with latent growth model and growth mixture model. Library data from 2014 to 2019 were collected from the National Library Statistics System, and 846 public libraries were analyzed. As results, the number of circulated books were decreased, but it was tempered. Next, with controlling the factor affecting the dependent variable, the size of collection and the number of participants in reading programs provided by public libraries were statistically significant. Lastly, 5 classes were identified by applying the growth mixture model, and the number of librarians was significantly associated with trajectory class membership.

• The Journal of the Korea Contents Association
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• v.18 no.11
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• pp.298-305
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• 2018

This paper explored the impact of adaptive efforts for the 4th Industrial Revolution(hereafter, 4IR) on social cohesion at national level. To examine this relationship, Latent Growth Model was applied to thirty one OECD membership countries, 2006-2015. Adaptive efforts for 4IR was measured by the 4IR Relative Readiness(WEF, 2016) and social cohesion was measured by Corruption Perception Index(Transparency International) and trust on politicians(WEF). Results showed that corruption perception significantly decreased by the 4IR Relative Readiness and legal protection(judiciary independency and corporate ethics) and trust on politicians significantly increased by judiciary independency. These results imply that public and corporate efforts for the 4IR does not necessarily have negative impact on social cohesion as long as legal protection such as judiciary independency and corporate ethics are equally pursuit at national level.

• (The)Korea Educational Review
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• v.24 no.1
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• pp.199-225
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• 2018

Using the 3rd to the 6th wave data from the Korean Children and Youth Panel Survey(KCYPS), we examined the effects of academic characteristics and social relations on the trajectories of the life satisfaction among adolescents. OLS results showed that male students were more satisfied with their lives than female students in the 3rd grade of middle school. As academic characteristics, academic achievement and the level of class adjustment improved life satisfaction but the amount of learning time spent had a negative effect on life satisfaction. However, the effect of academic achievement lost its statistical significance after including variables of social relations. Relationships with parents, teachers, and friends had positive effects on life satisfaction. The longitudinal analysis using the fixed effect estimation also showed a similar result of the associations among the variables to that in the OLS analysis. The life satisfaction gap between male and female students narrowed over time from the 3rd grade of middle school to the 2nd grade of high school. The effects of relationships with parents and friends showed significant effects on both female and male students, but the relationship with their teachers was significant only for female students. Based on the results, we discussed the issues of Korean education related to the life satisfaction among adolescents.

• Korean Journal of Culture and Social Issue
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• v.22 no.1
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• pp.65-85
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• 2016

In this study, we examined the longitudinal change of multicultural acceptability, peer relationship, and teacher relationship using latent growth curve modeling. This study used data from the second, third, and fourth waves of the middle school student cohort (N=2,178) of the Korean Children-Youth Panel Survey (KCYPS). The dependent variable was multicultural acceptability. The independent variables were peer relationship and teacher relationship. The major longitudinal findings of this study are as follows: First, peer relationships, teacher relationships and multicultural acceptability increased with time. Second, peer relationship showed a significant effect on the multicultural acceptability over time. Finally, the teacher relationship showed a significant effect on the multicultural acceptability over time. These results show differentiation with previous cross-sectional studies of multicultural acceptability. Furthermore, it is expected that this study will provide educational implications for the cultivation of multicultural acceptability.