Objectives This study identified the association between excessive exposure to screen media and behavioral and emotional problems in elementary school students. Methods A total of 331 parents of children aged 7–10 years were recruited from “The Kids Cohort for Understanding of Internet Addiction Risk Factors in Early Childhood (K-CURE)” study. Children’s demographics, household media ownership, screen time, and behavioral/emotional problems were assessed using a parental questionnaire. Children’s behavior/emotional problems were measured using the Korean version the of Child Behavior Checklist (K-CBCL) score. Results The total K-CBCL score in the screen overuse group was 51.18±9.55, significantly higher than 47.28±10.09 in the control group (t=2.14, p=0.05). For each subscale, the externalization score (51.65±10.14, 48.33±8.97, respectively; t=2.02, p<0.05), social problem score (55.41±6.11, 53.24±5.19, respectively; t=2.27, p<0.05), and rule breaking behavior score (55.71±6.11, 53.24±5.19, respectively; t=2.27, p<0.05) were significantly higher in the screen overuse group than in the control group. In addition, the screen overuse group also had a significantly higher usage rate than the control group, even if limited to smartphones, not only on weekdays (3.56±2.08, 1.87±2.02, respectively; t=-4.597, p<0.001) but also weekends (1.62±0.74, 1.19±0.83, respectively; t=-3.14, p=0.003). Conclusion The study suggested that screen media overuse patterns in children in Korea are particularly relevant to the excessive use of smartphones and are related to higher risks of emotional and behavioral problems.

We propose a method of forming metal nanoparticles or layers on the oxide by tunnelling current of the EOS (electrolyte-oxide-silicon) system. Electrical characteristics of the metal layer and particles obtained experimentally by the proposed method are compared with the electrolytemetal-oxide-silicon and the metal-oxide-silicon systems. Also, it is shown that the instability of the EOS system is caused by the H þ penetration into the oxide and is largely cured by applying alternative voltage to extract the H þ ions from the oxide. We show that the proposed technique can selectively deposit extremely thin metal layers on the active sites of the silicon surface in a self-alignment manner.