References
- G. W. Ladd, B. J. Kochenderfer & C. C. Coleman. (1996). Friendship quality as a predictor of young children's early school adjustment. Child Development, 67(3), 1103-1118. https://doi.org/10.2307/1131882
- M. Shin, S. H. Jeon & M. S. Yoo. (2012). Analysis of the Structural Relationship between Social Relationships, Self Esteem, Life Satisfaction, and School Adjustment in Early Adolescents. Korean Association of Child Studies, 33(1), 81-92. https://doi.org/10.5723/KJCS.2012.33.1.81
- G. W. Lee & M. A. Won. (2013). The Influence of Physical Self-Concept, Ego-Resilience and School Happiness of School Sports Club Activity Participation Middle School Student. Journal of Korean Society for the study of Physical education. 18(1), 147-161
- M. H. Kwon. (2015). The mediation effect of Social Withdrawal on the Relationship between Physical Education Record and Friendship in Children. Korean Journal of Elementary Physical Education, 20(4), 123-132.
- J. G. Parker. & S. R.. Asher. (1987). Peer relations and personal adjustment: Are low-accepted children at risk? Psychological Bulletin, 102, 357-389. https://doi.org/10.1037/0033-2909.102.3.357
- Statistics Korea. (2013). 2012 youth smartphone usage rate. Daejeon : Statistics Korea.
- Y. M. Kim & D. B. Kim. (2016). Mediating Effects of Self-Control on the Relationship between Smartphone Use and School Adjustment in Middle School Students. Korean Journal of Youth Studies, 23(3), 133-162. https://doi.org/10.21509/KJYS.2016.03.23.3.133
- Ministry of Gender Equality and Family. (2013). Results of diagnosis of internet . smartphone usage habits in 2013. Sejong: Ministry of Gender Equality and Family.
- C. H. Lee. (2013). A Study on Policy Measures to Protect Youths With The Spread of Smartphone. Seoul: National Youth Policy Institute.
- National Health Insurance Service. (2009). inquiry of health examinations. Seoul: National Health Insurance Service.
- B. S. Kim. (2006). Korean Version of International Physical Activity Questionnaire(IPAQ). Korean Journal of Family Medicine, 27(4), 348-357.
- S. Y. Hong, Y. J. Yang, H. K, Pa가 & B. S. Kim. (2006). Validation of Korean Youth Physical Activity Questionnaire (KYPAQ). Korean Journal of Physical Education, 45(5), 161-173.
- S. H. Lee et al. (2002). A Study on the Usage and Influence of Youth Mobile Phone(2002-1). Seoul: Samsung Life Public Welfare Foundation.
- S. M. Moon. (1977). A Study on the Background Characteristics and School Adjustment of Students. Gyeongsang National University Student Guidance Research, 4, 33-47.
- S. P. Lee. (1990). Analysis of differences in academic performance and behavioral characteristics according to school adaptation level. Unpublished master dissertation, Hongik Univ, Seoul, Korea
- B. S. Miin. (1991). The Effect of School Adaptation and Self-Concept on Academic Achievement. Unpublished master dissertation, Hongik Univ, Seoul, Korea
- M. Arnold. (2003). On the phenomenology of technology: The "Janus-faces" of mobile phones. Information and Organization, 13(4), 231-256. https://doi.org/10.1016/S1471-7727(03)00013-7
- S. J. Lee.(2014). Analysis of Smartphone Addiction Status and Risk among Elementary Students. Journal of the Korean association of Information Education, 18(2), 203-212. https://doi.org/10.14352/jkaie.2014.18.2.203
- H. W. Chung & S. D. Oh. (2008). The Difference between Aggression and Impulsiveness according to the State of the Internet Addiction of a Vocational High School Students in a Rural Area. Korea Journal of Counseling, 9(2), 601-614. https://doi.org/10.15703/kjc.9.2.200806.601
- X. Lu, J. Watanabe, Q. Liu, M. Uji, M.. Shono & T. Kitamura. (2011). Internet and mobile phone text-messaging dependency: Factor structure and correlation with dysphoric mood among Japanese adults. Computers in Human Behavior, 27(5), 1702-1709. https://doi.org/10.1016/j.chb.2011.02.009
- H. J. Seo. (2003). Relationships among Sport Participation, Peer Relations and Deviant Behaviors in Youth. Korean journal of physical education, 42(3), 143-152.
- H. J. Seo. & H. Ok(2015). Relationships among After-school Physical Activity Participation, Self-control, Smart Phone Addiction, and Adaptation to School Life in Youth. Journal of Sport and Leisure Studies, 60. 535-549
- M. K. Ji. Y. M. Kim & S. Y. Kim. (2017). The Structural Relationships among Sports Activity Engagement, Emotional Intelligence, Smart Phone Addiction and Antisocial Tendency for Adolescents. Korean Journal of Physical Education, 56(3), 271-282.
- H. G. Sun & J. S. Beak. (2015). The effects of particiating in sport club activity for depression, aggressiveness and self-resilience of middle school students depending on the extent of smartphone addiction. Korean Society For The Study Of Physical Education. 20(1), 107-123. https://doi.org/10.15831/JKSSPE.2015.20.1.107
- Y. S. Kim. & S. Y. Lee. (2017). A Study of Leisure Sport, Smart Phone Addiction, Sleep Quality, and School Adaptation among Elementary School Students. Journal of Research in Curriculum & Instruction. 21(6), 666-682 https://doi.org/10.24231/rici.2017.21.6.666
- D. H. Kim. J. D. Han. & K. J. Park. (2014). The Relationships of Smartphone Addiction and Mental Health according to Exercise hours of the After-School Exercise in Elementary School Students. Korean Journal of Elementary Physical Education, 20(2), 51-64.
- S. J. Tang. (2017). Relationships among Smart Phone Addiction, Anxiety and Life Satisfaction of After-school Physical Activity Participants in Youth. Journal of Sport and Leisure Studies, 70. 465-474.
- S. Y. Kim. S. H. Lee & H. S. Heang (2012). A Study of Smartphone Adoption: Considering User Traits. Entrue Journal of Information Technology, 11(3), 147-159.
- K. O. Kim & J. K. Seo. (2009). The Relationships between Leisure Sports Participation, Social Support, and Adjustment to School Life of High School Students. Korean Socoety of the Sociology Sport, 22(3), 125-140. https://doi.org/10.22173/jksss.2009.22.3.125
- B. K. Park. (2004). The Influence of Sport Activity Participation on School Life Adjustment and Self-fulfillment of Youth. Journal of Sport and Leisure Studies, 21, 633-644.
- G. S. Cho. (2016). The Mediation Effect of Mattering on the Relationship between Physical Competence and School Life Adjustments of Elementary Students Participating in Physical Activity after School. Korea journal of physical education, 55(4), 189-200.
- I. K. Chang & G. S. Cho. (2016). The Relationships between Subjective Physical Education Achievements and School Life Adjustments of Elementary School Students : Meditation Effects of Self-Esteem and Ego-Resilience, Korean Journal of Elementary Physical Education, 22(1), 93-104.
- J. U. Lee. J. S. Jung & Y. S. Kim. (2014). Analysis on the Relationship between sports activities participation and multicultural family elementary school students school life adaptation. Journal of Learner-Centered Curriculum and Instruction, 14(2), 131-146.
- H. M. Cho & H. J. Eum. (2014). The Analysis of Character and School Adjustment Based on After School Sport Participation Level of Elementary School Student. The Korean Journal of Elementary Physical Education, 19(4), 125-137.
- D. H. Park & J. S. Baik. (2014). School Adjustment and Smart Phone Addiction by Types of Adolescent Smart - Phone User on the Basis of Motivation -. 12(3), 37-47.
- J. H. Lee & H. W. Jang. (2016). The Effect of Self-control and Smartphone on Adaptability to Tourism High School Life. Korea Academic Society of Tourism Management, 31(3), 249-275.
- Williams, A L., & Merten, M. J. (2008). A Review of Online Social Networking Profiles by Adolescents: Implications for Future Research and Intervention. Adolescence, 43(17), 253-274. https://doi.org/10.1016/j.jadohealth.2007.01.015