Chang-Gun Lee

Chang-Gun Lee


Research Focus & Metrics

Academic Career Length

19Years (2008-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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4 July 2016 in Journal of Medical Internet Research
Verified
Journal Article
Open access
HWHyekyung Woo
Hyekyung Woo
YCYoungtae Cho
Youngtae Cho
ESEunyoung Shim
Eunyoung Shim
JLJong-koo Lee
Jong-koo Lee
CLChang-Gun Lee
Chang-Gun Lee
SKSeong Hwan Kim
Seong Hwan Kim
Journal of Medical Internet Research - International Scientific Journal for Medical Research, Information and Communication on the Internet

29 April 2024 in JMIR Mental Health
Verified
Journal Article
Open access
KCKwangsu Cho
Kwangsu Cho
MKMinah Kim
Minah Kim
YCYoungeun Cho
Youngeun Cho
JHJi-Won Hur
Ji-Won Hur
DKDo Hyung Kim
Do Hyung Kim
JKJun Soo Kwon
Jun Soo Kwon
Background: Limited awareness, social stigma, and access to mental health professionals hinder early detection and intervention of internet gaming disorder (IGD), which has emerged as a significant concern among young individuals. Prevalence estimates vary between 0.7% and 15.6%, and its recognition in the International Classification of Diseases, 11th Revision and Diagnostic and Statistical Manual of Mental Disorders, 5th Edition underscores its impact on academic functioning, social isolation, and mental health challenges. Objective: This study aimed to uncover digital phenotypes for the early detection of IGD among adolescents in learning settings. By leveraging sensor data collected from student tablets, the overarching objective is to incorporate these digital indicators into daily school activities to establish these markers as a mental health screening tool, facilitating the early identification and intervention for IGD cases. Methods: A total of 168 voluntary participants were engaged, consisting of 85 students with IGD and 83 students without IGD. There were 53% (89/168) female and 47% (79/168) male individuals, all within the age range of 13-14 years. The individual students learned their Korean literature and mathematics lessons on their personal tablets, with sensor data being automatically collected. Multiple regression with bootstrapping and multivariate ANOVA were used, prioritizing interpretability over predictability, for cross-validation purposes. Results: A negative correlation between IGD Scale (IGDS) scores and learning outcomes emerged (r166=–0.15; P=.047), suggesting that higher IGDS scores were associated with lower learning outcomes. Multiple regression identified 5 key indicators linked to IGD, explaining 23% of the IGDS score variance: stroke acceleration (β=.33; P<.001), time interval between keys (β=–0.26; P=.01), word spacing (β=–0.25; P<.001), deletion (β=–0.24; P<.001), and horizontal length of strokes (β=0.21; P=.02). Multivariate ANOVA cross-validated these findings, revealing significant differences in digital phenotypes between potential IGD and non-IGD groups. The average effect size, measured by Cohen d, across the indicators was 0.40, indicating a moderate effect. Notable distinctions included faster stroke acceleration (Cohen d=0.68; P=<.001), reduced word spacing (Cohen d=.57; P=<.001), decreased deletion behavior (Cohen d=0.33; P=.04), and longer horizontal strokes (Cohen d=0.34; P=.03) in students with potential IGD compared to their counterparts without IGD. Conclusions: The aggregated findings show a negative correlation between IGD and learning performance, highlighting the effectiveness of digital markers in detecting IGD. This underscores the importance of digital phenotyping in advancing mental health care within educational settings. As schools adopt a 1-device-per-student framework, digital phenotyping emerges as a promising early detection method for IGD. This shift could transform clinical approaches from reactive to proactive measures.

6 September 2024 in ICT Express
Verified
Journal Article
Open access
SMSangmi Moon
Sangmi Moon
CLChang-Gun Lee
Chang-Gun Lee
HLHuaping Liu
Huaping Liu
IHIntae Hwang
Intae Hwang

9 December 2008 in Mobile Networks and Applications
Verified
Journal Article
Closed access
PDF file
JKJung-Eun Kim
Jung-Eun Kim
JHJunghee Han
Junghee Han
CLChang-Gun Lee
Chang-Gun Lee

15 January 2018 in IEEE Transactions on Computers
Verified
Journal Article
Closed access
KKKang-Wook Kim
Kang-Wook Kim
YCYoungeun Cho
Youngeun Cho
JEJeongyoon Eo
Jeongyoon Eo
CLChang-Gun Lee
Chang-Gun Lee
Junghee HanJunghee Han
Junghee Han
Recent parallel programming frameworks such as OpenCL and OpenMP allow us to enjoy the parallelization freedom for real-time tasks. The parallelization freedom creates the time vs. density tradeoff problem in fluid scheduling, i.e., more parallelization reduces thread execution times but increases the density. By system-widely exercising this tradeoff, we propose optimal parameter tuning of real-time tasks aiming at maximizing the schedulability of multicore fluid scheduling. Our experimental study by both simulation and actual implementation shows that the proposed approach well balances the time and the density, and results in up to 80% improvement of the schedulability.

24 November 2013 in Journal of Network and Systems Management
Verified
Journal Article
Closed access
PDF file
PCPrasad Calyam
Prasad Calyam
LKLakshmi Kumarasamy
Lakshmi Kumarasamy
CLChang-Gun Lee
Chang-Gun Lee
FOFusun Ozguner
Fusun Ozguner