• Korean Journal of Culture and Social Issue
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• v.28 no.3
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• pp.331-352
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• 2022

This study used a latent growth curve models(LGCM) to examine longitudinal changes in youth's game usage, self-control and the longitudinal mediation effect of adaptive game use in the relationship between game usage and self-control. A four-year longitudinal data of 863 adolescents from the Game User Panel Survey, provided through participation in the 2019 Game User Panel Research Conference hosted by the Korea Creative Contents Agency, was used to verify the longitudinal mediation effect of adaptive game use. SPSS 21 was used to verify the normality of variables from each wave, and to conduct correlation analysis. Mplus 6.12 was used to verify the longitudinal mediation effect. The results are as follows. First, game usage, self-control and adaptive game yielded linear temporal growth. Second, latent growth curve models showed that the direct effect of game usage on self-control was insignificant, but game usage had a significant indirect effect on self-control through adaptive game use. Continuous adaptive gaming increased self-control. Third, sobel test results showed that both the initial value and change rate of adaptive game use had a full-mediation effect, confirming the longitudinal mediation effect. This study verified the longitudinal change of self-control affected by change in game usage and adaptive game use.

• Korean Journal of Social Welfare Studies
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• v.48 no.4
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• pp.59-89
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• 2017

Changes in the public welfare attitudes are very important to the welfare politics and policy. Considering that variability of public welfare attitudes has been ignored in previous studies, we analyzed welfare attitudes changes at individual level in Korea. Using the longitudinal data from the Additional Survey of 2010/2013/2016 Korea Welfare Panel Survey, we analyzed the changes in public welfare attitudes during 2010th-2016th years. Major findings are as follows. First, one of the findings from analysis is that the public welfare attitudes are very active and dynamic in Korea. This finding is contradiction to the results of the previous researches that are point to the stability or inertia of the public welfare attitudes in western welfare states and also in Korea. Second, occurrences of the welfare attitudes change are related with various individual characteristics; income status, occupation status, age, region, sex, political ideology, etc. These results from this study on the welfare attitudes change suggest that dynamics of the Korea welfare politics in recent years reflected the dynamic changes in public welfare attitudes. And, they suggest that Korea welfare politics are transformed from the traditional classes welfare politics to the new welfare politics which are influenced by various interests of the socio-demographic groups.

• Journal of the Korean Geographical Society
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• v.39 no.5 s.104
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• pp.722-734
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• 2004

Longitudinal profiles of bedrock rivers play a fundamental role in landscape history by setting the boundary conditions for landform evolution. Longitudinal profiles are changed with climatic conditions, lithology and tectonic movements. Tectonic movement is an important factor controlling longitudinal profiles, especially in tectonically active area where uplift rates are regarded as a major factor controlling channel gradient. However study on bedrock channel has made little progress, because controls over bedrock river incision are yet to be clarified. Previous numerical simulations have used a simple diffusion model, which links together the overall processes of bedrock channel erosion as in other landform evolution models. In this study, previous bedrock incision models based on physical processes (especially abrasion) are reviewed and new modifications are introduced. Using newly formulated numerical model, the role of spatial pattern and intensity of tectonic uplift on changes in river longitudinal profile was simulated and discussed.

• Journal of Korean Neurosurgical Society
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• v.43 no.6
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• pp.259-264
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• 2008

Objective : Total laminectomy (TL) is an effective surgical technique for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) along multiple levels. However, kyphosis and probable neurological deterioration have been frequently reported after laminectomy. We analyzed the changes in the cervical curvature after TL and subsequent changes in neurological status. Methods : We retrospectively reviewed the records of 14 patients who underwent TL for the treatment of cervical OPLL between Jan. 1998 and Dec. 2003. TL was selected according to the previously determined criteria. The curvature of the cervical spine was visualized on a lateral cervical spine X-ray and measured using Ishihara's Curvature Index (CI) before the operation and at the last follow-up examination. Perioperative neurological status was estimated using the modified Japanese Orthopedic Association score and the Improvement Rate (IR) at the same time as the images were evaluated. Results : The mean age of the patients was 57 years, the male/female ratio was 10:4, and the mean follow-up period was 41 months. The mean number of OPLL was 4.9, and the mean number of operated levels was also 4.9. The CI decreased after TL (p=0002), which was indicative of a kyphotic change. However, this kyphotic change showed no correlation with the length of the follow-up period, number of operated levels and preoperative CI. Neurological examination at the last follow-up showed an improved neurological status in all patients (p=0.001). There was no neurological deterioration in any case during the follow-up period. Moreover, there was no correlation between IR and the degree of kyphotic change. Postoperative complications, such as C5 radiculopathy and epidural bleeding, resolved spontaneously without neurological sequelae. Conclusion : Kyphotic change was observed in all but one patient who underwent TL for the treatment of cervical OPLL. However, we did not find any contributing factors to kyphosis or evidence of postoperative neurological deterioration.

• Journal of the Korea Society of Computer and Information
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• v.26 no.11
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• pp.209-215
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• 2021

The purpose of this study is to identify changing patterns in multicultural adolescent's life satisfaction and to explore longitudinal changes in the effects of acculturation stress, self-esteem and family support on the changes in life satisfaction. For this purpose, the survey data from the 4th to 6th years of the Multicultural Youth Panel Survey were used for the analysis. As a result of the analysis, life satisfaction, self-esteem, and family support decreased for 3 years through each linear change model. As a result of examining the longitudinal mediating effects of self-esteem and family support between acculturation stress and life satisfaction through the multivariate potential growth model, the mediating effect of self-esteem and family support was confirmed. Based on these results, practical implications for improving life satisfaction, self-esteem, and family support of multicultural youth were presented.

• Journal of the Korea Society of Computer and Information
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• v.26 no.12
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• pp.265-271
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• 2021

The purpose of this study is to make practical suggestions to help multicultural adolescents' academic adaptation. For this purpose, changes in the academic adaptation of multicultural adolescents were identified, and longitudinal changes in self-esteem were explored in the relationship between bicultural acceptance attitude and academic adaptation. The data from the panel survey of multicultural youth of the Korea Youth Policy Institute was used for the analysis. The result of analyzing the longitudinal mediating effects of self-esteem between bicultural acceptance and academic adaptation through the multivariate potential growth model, the mediating effects of self-esteem was confirmed. Based on these results, the practical implications for enhancing the bicultural acceptance attitude, academic adaptation, and self-esteem of multicultural youth were presented.

• Journal of the Korean Society for Library and Information Science
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• v.52 no.4
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• pp.179-194
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• 2018

The purpose of this study is to discuss the application of the Latent Growth Model to measure the outcomes of public library. For outcome measurements, library circulation data were collected to identify longitudinal changes of library users' reading habit. The latent growth model was applied to statistically test the changes over time. The circulation data of 95,962 users registered in some public libraries in Seoul, ranged between 2010 and 2015, were analyzed using unconditional model, conditional model, and growth mixture model which all are called the latent growth model. The results show that the intercept of the model is 4.19 and the slop is 0.24 in the linear growth model. The gender difference in two latent variables including intercept and slop was a shade difference. The result from the growth mixture model analysis, additionally indicates that the number of books checked out by children under age 10 is rapidly increased. The application of the latent growth model in library fields is expected to widely spread out for the longitudinal data analysis.

• Journal of Cardiovascular Imaging
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• v.31 no.2
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• pp.98-104
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• 2023

BACKGROUND: We aimed to investigate left ventricular (LV) global longitudinal strain (GLS) in end-stage renal disease patients and its change after kidney transplantation (KT). METHODS: We retrospectively reviewed patients who underwent KT between 2007 and 2018 at two tertiary centers. We analyzed 488 patients (median age, 53 years; 58% male) who had obtained echocardiography both before and within 3 years after KT. Conventional echocardiography and LV GLS assessed by two-dimensional speckle-tracking echocardiography were comprehensively analyzed. Patients were classified into three groups according to the absolute value of pre-KT LV GLS (|LV GLS|). We compared longitudinal changes of cardiac structure and function according to pre-KT |LV GLS|. RESULTS: Correlation between pre-KT LV EF and |LV GLS| were statistically significant, but the constant was not high (r = 0.292, p < 0.001). |LV GLS| was widely distributed at corresponding LV EF, especially when the LV EF was > 50%. Patients with severely impaired pre-KT |LV GLS| had significantly larger LV dimension, LV mass index, left atrial volume index, and E/e' and lower LV EF, compared to mildly and moderately reduced pre-KT |LV GLS|. After KT, the LV EF, LV mass index, and |LV GLS| were significantly improved in three groups. Patients with severely impaired pre-KT |LV GLS| showed the most prominent improvement of LV EF and |LV GLS| after KT, compared to other groups. CONCLUSIONS: Improvements in LV structure and function after KT were observed in patients throughout the full spectrum of pre-KT |LV GLS|.

• Journal of the Korean Geotechnical Society
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• v.15 no.4
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• pp.99-112
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• 1999

When there exists a fault zone ahead of the tunnel face and a tunnel is excavated without perceiving its existence, it will cause stress concentration in the region between the tunnel face and the fault zone because of the influence of the fault zone on the arching phenomena. Because the underground structure has many unreliable factors in the design stage, the prediction of a fault zone ahead of the tunnel face by monitoring plans during tunnel construction and the rapid establishment of appropriate support system are required for more economical and safer tunnel construction. Recent study shows that longitudinal displacement changes during excavation due to the change of rock property, and if longitudinal displacement and settlement, which are measured in the field, are considered together in displacement analysis, the prediction of change in rock mass property is possible. This study provided the method for the prediction of fault zones by analyzing the changes of L/C and (Ll-Lr)/C ratio (L= longitudinal displacement at crown, C = settlement at crown, Ll = longitudinal displacement at left sidewall, Lr = longitudinal displacement at right sidewall) and the stereographic projection of displacement vectors which were obtained from the 3-D numerical analysis of hybrid method in various initial stress conditions.

• 한국노년학
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• v.29 no.2
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• pp.729-742
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• 2009

The purpose of this study was to examine the changes of emotion experiences in old age and confirm the effects of emotional characteristics on the subjective well-being in old age by the longitudinal study. This longitudinal study started from 2003 and every two year we performed panel study. We analysed the data from old participants who participated tree-times(2003, 2005, 2007)and over 65 year-old. Finally, 844 old participants(male, 340; female, 504)' data were analysed. The elderly experienced more positive emotions than negatives and these results represented affective optimization. We performed mixed ANOVA method and confirmed significant change of emotion experiences during 6 years. Positive emotion experiences and negative emotion experiences were decreased as they get older. We also examined the effects of emotional experiences on the subjective well-being. In results, emotion experiences were more effective than the demographic variables for maintaining subjective well-being in old age. Decreasing negative emotion experiences and increasing positive emotion experiences can keep happy life up in old age. The importance of the quality of emotional life in old age and the necessity of longitudinal study of aging were discussed.