• Journal of Preventive Medicine and Public Health
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• v.32 no.2
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• pp.177-182
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• 1999

Objectives: To reexamine the association between air pollution and daily mortality in Seoul, Korea using a method of meta-analysis with the data filed for 1991 through 1995. Methods: A separate Poisson regression analysis on each district within the metropolitan area of Seoul was conducted to regress daily death counts on levels of each ambient air pollutant, such as total suspended particulates (TSP), sulfur dioxide $(SO_2)$, and ozone $(O_3)$, controlling for variability in the weather condition. We calculated a weighted mean as a meta-analysis summary of the estimates and its standard error. Results: We found that the p value from each pollutant model to test the homogeneity assumption was small (p<0.01) because of the large disparity among district-specific estimates. Therefore, all results reported here were estimated from the random effect model. Using the weighted mean that we calculated, the mortality at a $100{\mu}g/m^3$ increment in a 3-day moving average of TSP levels was 1.034 (95% Cl 1.009-1.059). The mortality was estimated to increase 6% (95% Cl 3-10%) and 3% (95% Cl 0-6%) with each 50 ppb increase for 9-day moving average of SO2 and 1-hr maximum O3, respectively. Conclusions: Like most of air pollution epidemiologic studies, this meta-analysis cannot avoid fleeing from measurement misclassification since no personal measurement was taken. However, we can expect that a measurement bias be reduced in a district-specific estimate since a monitoring station is hefter representative cf air quality of the matched district. The similar results to those from the previous studios indicated existence of health effect of air pollution at current levels in many industrialized countries, including Korea.

• The Korean Journal of Applied Statistics
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• v.29 no.7
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• pp.1311-1327
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• 2016

We propose a multi-state model for analyzing semi-competing risks data with interval-censored or missing intermediate events. This model is an extension of the 'illness-death model', which composes three states, such as 'healthy', 'diseased', and 'dead'. The state of 'diseased' can be considered as an intermediate event. Two more states are added into the illness-death model to describe missing events caused by a loss of follow-up before the end of the study. One of them is a state of 'LTF', representing a lost-to-follow-up, and the other is an unobservable state that represents the intermediate event experienced after LTF occurred. Given covariates, we employ the Cox proportional hazards model with a normal frailty and construct a full likelihood to estimate transition intensities between states in the multi-state model. Marginalization of the full likelihood is completed using the adaptive Gaussian quadrature, and the optimal solution of the regression parameters is achieved through the iterative Newton-Raphson algorithm. Simulation studies are carried out to investigate the finite-sample performance of the proposed estimation procedure in terms of the empirical coverage probability of the true regression parameter. Our proposed method is also illustrated with the dataset adapted from Helmer et al. (2001).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.1
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• pp.95-106
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• 2017

The purpose of this study was to identify the effects of non-pharmacological interventions for Korean adults with insomnia. Literature review was performed for articles published between 2000 and 2016 in electronic databases. Sixteen articles met the inclusion criteria. Data were analyzed by R version 3.3.1 for windows. Meta-analysis was performed using the random effects model; the overall effect size of non-pharmacological interventions on sleep was significantly large (Hedges' g=2.36, 95% CI: 1.44~3.28). For heterogeneity, a moderator analysis was performed using the study design, participants, age group, intervention, presence of hospitalization, and sleep measurement. There was a statistically significant difference between the effects of moderator variables, except for the study design and participants. Of the interventions, auricular acupressure reported to have the largest effect size on sleep. The findings in this study indicate that non-pharmacological interventions have a positive effect on sleep, providing objective evidence to improve sleep in adults with insomnia using effective interventions.

• Journal of Life Science
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• v.32 no.10
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• pp.821-831
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• 2022

This study evaluated the effects of physical touch play programs in children through a systematic literature review and meta-analysis. A literature search for journal articles published before August 2022 was conducted using KERIS, KISS, DBpia, and ScienceON. The keywords used for the search were 'child', 'infant', 'physical touch', 'physical touch play', 'physical touch activities' and 'physical touch play program'. For the study's purpose, seven studies were selected through a systematic process of using several databases and were used to estimate the effect size of physical touch play programs. A meta-analysis was performed using a random effects model, and the effect size on cognitive function was calculated. Hedges' g of the physical touch play program was 6.20 (95% CI: 3.74-8.66), indicating a large effect size. To determine heterogeneity (I2= 95.4%, Q = 417.30, p<0.001), moderator analysis was performed using the total number of times and intervention duration. The total number of times was statistically significant; the other moderators did not differ significantly. This study systematically analyzed the results of physical touch play programs on children in Korea. It also provides insights that can be applied to the design of physical touch play programs for children. To present more evidence that supports the effectiveness of physical touch programs, further research is warranted.

• The Journal of Korean Academy of Sensory Integration
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• v.18 no.1
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• pp.56-72
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• 2020

Objective : The purpose is to analyze the effects of parent training interventions in reducing the symptoms of Attention Deficit Hyperactivity Disorder (ADHD) and to provide a basis for the effects. Methods : We collected literature published in international academic journals from 2009 to 2019 through ProQuest and Scopus databases. The search key terms were (ADHD OR Attention Deficit Hyperactivity Disorder) AND (Parent OR Mother OR Father) AND (Training OR Program OR Therapy OR Intervention) AND (Randomized OR Randomised OR Randomly). The PEDro scale was used to evaluate the quality of the studies, and a meta-analysis was conducted through Comprehensive Meta-Analysis 3.0. Results : Of 628 studies that we reviewed, 20 were eligible for inclusion. of parental training interventions for children with ADHD appeared close to a medium effect size while parent-child interventions (0.639) appeared to have a medium to large effect size. Oppositional defiant behavior and conduct disorder (0.737) in children and children's emotions (0.679) appeared close to a large effect size. ADHD symptoms hyperactivity and impulsivity (0.590) and child behavior (0.521) appeared to be over a medium effect size. We chose a random-effects model since heterogeneity tests showed significant results. Conclusion : We were able to confirm the effects of parent training interventions on the symptoms of children with ADHD. This will be used as evidence to provide a clinical basis for occupational therapists. More research related to parental training interventions should be carried out to ensure better reporting in the future.

• Journal of Korean Society of Transportation
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• v.35 no.4
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• pp.307-320
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• 2017

The objective of this study is to identify the effectiveness of ESC(Electronic Stability Control) based on a meta analysis technique. Accident Rate, Fatal Crash Rate, Loss of Control Crash Rate were set as indexes of traffic safety evaluation. Also, reviews on the effectiveness of ESC were collected using keyword, 'ESC'. As a result, the Effect size of accident rate odd ratio was 0.90. When ESC system was applied on vehicles, accident rate decreased by 10%. Also, the Effect size of fatal crash rate odd ratio was 0.64. When ESC system was applied on vehicles, fatal crash rate decreased by 36%. Lastly, the Effect size of loss of control crash rate odd ratio was 0.73. When ESC system was applied on vehicles, loss of control crash rate decreased by 27%. The outcome of this study would be effectively used for developing polices and regulations for ESC installation obligation of commercial vehicles.

• Journal of the Korean Data and Information Science Society
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• v.21 no.6
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• pp.1155-1169
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• 2010

This study considers movement-based registration (MBR). In MBR, a mobile station (MS) performs location registration whenever the number of entering cells reaches the specified movement threshold M. MBR is simple and its implementation is quite straightforward. However, it may result in more registrations than other similar schemes. An improved MBR scheme called MBIR (MBR with implicit registration) was proposed to reduce registration cost of MBR and its approximated performance was analyzed. In this study, we point out some problems of the previous analysis method and propose an exact analysis method of MBIR. Using the exact analysis method, we show that the previous analysis includes considerable errors and improvement of MBIR in our study seems to be larger than in the previous study.

• Journal of the Korean Data and Information Science Society
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• v.27 no.5
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• pp.1375-1387
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• 2016

The purpose of this study was to evaluate the effect of exercise on cognitive function in the elderly through a systematic literature review and meta-analysis. For the study purpose, 14 studies were selected through a systematic process of using several databases and 11 studies were used to estimate the effect size of exercise on cognitive function. Meta-analysis was performed using a random effects model, and the effect size on cognitive function was calculated. The effect size for cognitive function of exercise intervention was Hedges' g=1.05 (95% CI: 0.61~1.50), indicating a large effect size. For heterogeneity, moderator analysis was performed using intervention, number of times per week, intervention duration, and cognitive function measurement. Cognitive function measurement was statistically significant, the other moderators did not significant difference. Results support that exercise has significant positive effects on cognitive function in elderly in korea. It also provided a basis that can be applied to exercise intervention design for cognitive function.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.65-75
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• 2015

This paper analyzes the determinants of wage for the college and university graduates utilizing both individual-level and industry-level variables. We note that wage determination has multi-level structure in the sense that individual wage is influenced by individual-level variables (level-1) and industry-level (level-2) variables. Then, the assumption that individual wage is independent in the classical regression is violated. Therefore, this paper utilizes the hierarchical linear model (HLM). The major results are the followings. First, the multiple correspondence analysis including level-1 and 2 variables reveals that both level 1 and level 2 variables affects individual wages judging from the fact that the values of level 1 and level 2 variables differ across the different level of individual wage groups. Second, the decision tree analysis including level-1 and 2 variables shows that the most influential variable in wage determination is industry-level wage and the next is industry-level working hour, ages and sex in the decling order in. This suggests that the utilization of the HLM is appropriate since the characteristics of industry is important in determining the individual wage. Third, it is shown that the HLM model is the best compared to the other models which do not take level-1 and level-2 variables simultaneously into account.

• Journal of Korea Technology Innovation Society
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• v.21 no.2
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• pp.522-559
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• 2018

In this study, we reviewed and analyzed the influencing factors of technology transfer performance in the previous studies (52 domestic journals and theses) and classified the various influencing factors into 6 top factors and 13 sub-factors based on the theoretical background. The study results of previous articles were analyzed by meta-analysis method so as to calculate the overall average effect size of influencing factors of technology transfer performance. As the result, the overall effect size (ESr) calculated through meta-analysis applying random effect model is .269, which corresponds to the medium effect size. By comparing effect sizes of influencing factors, the four(4) key influencing factors were also identified, which are 'number of researchers', 'dedicated organization', 'possess technology', and 'external cooperation'. The technology transfer performance are divided into three types: the number of technology transfers, technology transfer income, and other technology transfer performances. The major influencing factors of each type are derived through meta-analysis at the sub-category level. As moderator variables, the paper type and the data type were analyzed but no significant results were obtained. Since this research is limited to the technology transfer, it is necessary to carry out the study related to the influencing factors on the technology commercialization as following study.