• Journal of Convergence for Information Technology
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• v.9 no.4
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• pp.78-87
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• 2019

The study examined how job satisfaction and pay level can affect on old salary workers over time using longitudinal data and longitudinal data analysis. The KLoSA 6-period panel data was used which contains alternate year from 2006 to 2016. In addition, Gender and Age is also considered as moderating variables. As result, the initial value and the slope of pay level influenced the initial value and the slope of job satisfaction, vice versa. It implicates the two factors of pay level and job satisfaction are interrelated. Based on the results of this study, limitations and suggestions were discussed for further research.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.3
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• pp.224-232
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• 2015

In order to develop an active safety system which avoids or mitigates collisions with preceding vehicles such as autonomous emergency braking (AEB), accurate state estimation of the nearby vehicles is very important. In this paper, an algorithm is proposed using 3 dynamic models to better estimate the state of a vehicle which has various dynamic patterns in both longitudinal and lateral direction. In particular, the proposed algorithm is based on the Interacting Multiple Model (IMM) method which employs three different dynamic models, in cruise mode, lateral maneuver mode and longitudinal maneuver mode. In addition, a Probabilistic Data Association Filter (PDAF) is utilized as a data association algorithm which can improve the reliability of the measurement under a clutter environment. In order to verify the performance of the proposed method, it is simulated in comparison with a Kalman filter method which employs a single dynamic model. Finally, the proposed method is validated using radar data obtained from the field test in the proving ground.

• Journal of Digital Convergence
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• v.13 no.8
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• pp.267-279
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• 2015

The study aimed to examine the longitudinal relationship between addictive use of mobile phones and learning activities for elementary school students and to analyze (1)temporal changes of the addictive use of mobile phones and learning activities, (2)temporal relationship between them, and (3)multiple and complex group analysis across gender on the relationship. For the study, 3-year longitudinal data(2010-2012) of the Korean Children and Youth Panel Survey and autoregressive cross-lagged modeling were used. The findings showed that the addictive use of mobile phones and learning activities had a significant positive effect on the future selves of children over time. The addictive use of mobile phones influenced positively subsequent learning activities, but, the learning activities did not affect the addictive use of mobile phones. Further, there were no significant gender differences in the longitudinal relationship. The study provided the useful data to make guidelines on how to protect mobile phone addiction for elementary school students.

• Women's Health Nursing
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• v.28 no.2
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• pp.123-133
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• 2022

Purpose: This study investigated the trajectory of subjective health status in married postmenopausal women and aimed to identify predictive factors affecting subjective health status. Methods: Data were obtained from women who participated in wave 4 (2012) of the Korean Longitudinal Survey of Women & Families Longitudinal Study and continued to the latest phase (wave 7, 2018). A latent growth model (LGM) was used to analyze data from 1,719 married postmenopausal women in the framework of the ecological system theory. Results: The mean age of the participants at wave 4 was 56.39±4.71 years, and the average subjective health status was around the midpoint (3.19±0.84). LGM analysis confirmed that subjective health status decreased over time (initial B=3.21, slope B=-0.03). The factors affecting initial subjective health were age, body mass index, frequency of vigorous physical activity (microsystem level), marital satisfaction (mesosystem level), and medical service utilization (macrosystem level). Medical service utilization and the frequency of vigorous physical activity were identified as predictive factors affecting the slope in subjective health status. The model fit was satisfactory (TLI=.92, CFI=.95, and RMSEA=.04). Conclusion: This analysis of the trajectory of subjective health status of married postmenopausal women over time confirmed that subjective health is influenced by overall ecological system factors, including the microsystem, mesosystem, exosystem, macrosystem, and chronosystem. Therefore, it is necessary to assess physical activity and support policies promoting access to medical services in order to improve the subjective health status of married postmenopausal women.

• Journal of the Korea Concrete Institute
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• v.22 no.2
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• pp.273-282
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• 2010

The purposes of this study are to verify the existing model and to propose a rational model for the fracture characteristic of reinforcing steel which is manufactured in Korea being subjected to cyclic loading. This investigation deals with modeling of the low-cycle fatigue behavior for longitudinal reinforcement steel of reinforced concrete bridge substructure (piles and columns of piers). The proposed low-cycle model of longitudinal steel is modeled based on 81 experimental data. The non-linear analysis program was developed using the proposed low-cycle model. The non-linear analysis are applied to the 6 circular bridge column test results and the accuracy of proposed model is discussed.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.541-548
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• 2020

This study aimed to explain the factors that influenced an individual's decision to migrate. The method of analysis in this study was the estimation of the probit regression model with data from the Indonesian Family Life Survey (IFLS-5), which covered 30,000 individuals from 13 provinces in Indonesia. Data from IFLS-5 were longitudinal data, meaning that the study was looking for data consistently to get reliable data from respondents. The research variables to determine the individual's decision to migrate were education level, income level, employment status, marital status, land ownership status, health quality, gender, residence status, and poverty status. Individual decision to migrate as a dependent variable was placed as a dummy variable. The results showed that the level of education, income level, employment status, marital status, land ownership status, health quality, and poverty status significantly influenced an individual's decision to migrate. Meanwhile, gender and residence status did not significantly affect an individual's decision to migrate. This research recommends that it is necessary to pursue a policy of economic equality between regions because economic factors are the main trigger for an individual's decision to migrate. Policies to overcome economic disparities among regions will reduce the individual's decision to migrate.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1626-1635
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• 2016

This study examines whether online game motivation, with social and expedition needs, are associated with the degree of loneliness among young adolescents. Using data from a survey of 2014 elementary-, middle- and high-school students in South Korea, a three-wave online survey was conducted to collect data from online players. Two latent growth cause-and-effect models were developed to test whether online game motivation influences degree of loneliness. Results showed that both social and expedition needs are positively associated with loneliness. This study contributes to the knowledge of the underlying needs for a player with loneliness and also highlights the social and expedition needs as potential therapeutic factors.

• Research in Community and Public Health Nursing
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• v.28 no.1
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• pp.13-22
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• 2017

Purpose: The aim of this study is to examine the reciprocal causal relationship between social activities and health with reference to the cognitive function level among community-dwelling older adults. Methods: We conducted a longitudinal data analysis using the $4^{th}$ (Time 1) and $5^{th}$ (Time 2) waves from the Korean Longitudinal Study of Ageing adopting cross-lagged panel analysis (CLPA). Results: A total of 3,473 community-dwelling older adults were included in the analysis: 2,053 in the normal cognitive function group, 912 in the mild cognitive impairment group, and 508 in the moderate to severe cognitive impairment group. The CLPA revealed that higher levels of social activities at Time 1 significantly influenced better subjective health perception at Time 2 in all three groups. In addition, better subjective health perception at Time 1 significantly influenced higher levels of social activities at time 2 only in the normal cognitive function group. Conclusion: This study demonstrates that participating in social activities has positive effects on health regardless of the cognitive function level in community-dwelling older adults. This finding suggests that there is a need to develop strategies that can be used to encourage older adults with cognitive decline to maintain participation in social activities.

• The Mathematical Education
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• v.61 no.1
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• pp.127-156
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• 2022

This study used the data of students from the 6th grade to the 3rd grade of middle schoolin the Korean Educational Longitudinal Study 2013 and classified them into subgroups with similar longitudinal changes in math academic achievement. In addition, the influence of longitudinal changes in the group's academic self-concept and teachers and parents academic support on the longitudinal changes in math academic achievement were analyzed, either directly or indirectly. As a result of the analysis, it was found that the academic self-concept of each group had a positive influence on the academic achievement in mathematics. In addition, the academic support of teachers and parents was found to have a positive influence on the academic achievement in mathematics through the mediating of the academic self-concept. In terms of direct and indirect influence on academic self-concept and math vertical scale scores, it was found that teachers' academic support had more influence than parents' academic support. The educational implications of these points were discussed.

• Tunnel and Underground Space
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• v.18 no.5
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• pp.338-342
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• 2008

Longitudinal deformation profile(LDP) has been obtained mostly by numerical analysis. In this study, LDP was plotted by measured data from horizontal inclinometer and crown settlement. Deformation of foe ahead was determined by comparing to the maximum deformation point and deformation of after excavation was determined by regression of the measured crown settlement data. The result shows that crown deformation began as f3r as 3D ahead of the face. Crown settlement at the face was 40% of ultimate deformation, which was 10% higher than numerical results, and the deformation converged after excavation of 4D.