• Journal of Biomedical Engineering Research
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• v.33 no.1
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• pp.47-52
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• 2012

The purpose of this study is to investigate whether medication and deep brain stimulation (DBS) have differential effects on the speed and amplitude of bradykinesia in patients with Parkinson's disease (PD). Five PD patients with implanted DBS electrodes (age: $60.6{\pm}7.4yrs$, H&Y stage: $3.1{\pm}0.2$) participated in this study. FT (finger tapping) movement was measured using a gyrosensor system in four treatment conditions: Med (Medication)-off/DBS-off, Med-off/DBS-on, Med-on/DBS-off and Med-on/DBS-on. Quantitative measures representing average speed and amplitude of FT movement included root-mean-squared (RMS) angular velocity and RMS angle. One-way repeated measures ANOVA showed that RMS angular velocity of Med-on/DBS-on was significantly greater than those of Med-off/DBS-off and Med-off/DBS-on (p < 0.01) whereas RMS angle was not different among conditions (p = 0.06). Two way repeated measures ANOVA showed that only medication improved RMS angular velocity (p < 0.01), whereas both medication and DBS had no significant effect on RMS angle (p > 0.02). Effect size of RMS angular velocity was greater than that of RMS angle in both medication and DBS. This suggests that medication and DBS have differential effects on FT bradykinesia and velocity and amplitude impairments may be associated with different functional aspects in PD.

• Journal of Korean Academy of Nursing
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• v.46 no.5
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• pp.642-652
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• 2016

Purpose: In this single repeated measures study, an examination was done on the effects of dialysate flow rate on dialysis adequacy and fatigue in patients receiving hemodialysis. Methods: This study was a prospective single center study in which repeated measures analysis of variance were used to compare Kt/V urea (Kt/V) and urea reduction ratio (URR) as dialysis adequacy measures and level of fatigue at different dialysate flow rates: twice as fast as the participant's own blood flow, 500 mL/min, and 700 mL/min. Thirty-seven hemodialysis patients received all three dialysate flow rates using counterbalancing. Results: The Kt/V ($M{\pm}SD$) was $1.40{\pm}0.25$ at twice the blood flow rate, $1.41{\pm}0.23$ at 500 mL/min, and $1.46{\pm}0.24$ at 700 mL/min. The URR ($M{\pm}SD$) was $68.20{\pm}5.90$ at twice the blood flow rate, $68.67{\pm}5.22$ at 500 mL/min, and $70.11{\pm}5.13$ at 700 mL/min. When dialysate flow rate was increased from twice the blood flow rate to 700 mL/min and from 500 mL/min to 700 mL/ min, Kt/V and URR showed relative gains. There was no difference in fatigue according to dialysate flow rate. Conclusion: Increasing the dialy-sate flow rate to 700 mL/min is associated with a significant increase in dialysis adequacy. Hemodialysis with a dialysate flow rate of 700 mL/min should be considered in selected patients not achieving adequacy despite extended treatment times and optimized blood flow rate.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.201-210
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• 2015

Repeated measurements on each variables of interest often arise in bioscience or medical research. We need to account for correlations among repeated measurements to assess the correlation between two variables in the presence of replication. This paper reviews methods to estimate a correlation coefficient between two variables in repeated measurements using the variance-covariance matrix of linear mixed effect models. We analyze acoustic radiation force impulse imaging (ARFI) data to assess correlation between three shear wave velocity (SWV) measurements in liver or spleen and spleen length by ultrasonography. We present how to obtain parameter estimates for the variance-covariance matrix and correlations in mixed effects models using PROC MIXED in SAS.

• Survey Research
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• v.9 no.2
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• pp.1-27
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• 2008

Problems of incomplete data are pervasive in statistical analysis. In particular, incomplete data have been an important challenge in repeated measures studies. The objective of this study is to give a brief introduction to missing data mechanisms and conventional/recent missing data methods and to assess the performance of various missing data methods under ignorable and non-ignorable missingness mechanisms. Given the inadequate attention to longitudinal studies with missing data, this study applied recent advances in missing data methods to repeated measures models and investigated the performance of various missing data methods, such as FIML (Full Information Maximum Likelihood Estimation) and MICE(Multivariate Imputation by Chained Equations), under MCAR, MAR, and MNAR mechanisms. Overall, the results showed that listwise deletion and mean imputation performed poorly compared to other recommended missing data procedures. The better performance of EM, FIML, and MICE was more noticeable under MAR compared to MCAR. With the non-ignorable missing data, this study showed that missing data methods did not perform well. In particular, this problem was noticeable in slope-related estimates. Therefore, this study suggests that if missing data are suspected to be non-ignorable, developmental research may underestimate true rates of change over the life course. This study also suggests that bias from non-ignorable missing data can be substantially reduced by considering rich information from variables related to missingness.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.93-104
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• 2023

This study was designed to evaluate effects of Patients Empowerment Program for Schizophrenia (PEPS) on Empowerment, Internalized Stigma, Self-esteem, and Quality of Life, in people with chronic schizophrenia living in a rural community. A non-equivalent control group repeated measures design was used. Participants were 22 persons with chronic schizophrenia enrolled from O Province Mental Health Welfare Center, South Korea. (experimental group= 10, control group = 12). The PEPS was administered to the experimental group, consisting of 16 sessions delivered twice a week for 8 weeks. SPSS/WIN 26.0 was used to analyze the collected data using χ²-test, independent t-test, Fisher's exact test, and repeated measures ANOVA. Upon completion of PEPS, the experimental group showed a significantly increased in Self-esteem (F=6.09, p=.005) and Quality of Life (F=3.37, p=.044) as compared to the control group. However, there was no significant difference between the two groups between Empowerment and Internalized Stigma. The results suggest that the PEPS may be an effective intervention for improving Self-esteem and Quality of Life.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.3
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• pp.297-302
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• 2015

To prevent cargo accidents by repeated loads, a continuous monitoring for securing rope or additional safety measures are needed, but most of prevention measures have been conducted only by operator's own experience not a quantitative assessment. Hence, the Load-Displacement curve and approximation formula of securing rope were drawn in this research for a quantitative assessment and simplified measurement on a tension of securing rope using a tensiometer. Moreover, a com parison was conducted between m easuring tension and calculated tension on securing rope with portable tensiometer, 'Load-Displacement' approximation formula. The calculated tension of securing rope is obtained 153.3kfg using the formula and that result has not much difference with initial tension 150.0kgf. Lastly, an analysis of the characteristics of various ropes was suggested to enhance the reliability about quantitative assessment of securing rope's tension through further research.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.3
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• pp.232-239
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• 2022

This study performed qualitative and quantitative risk assessment of equipment for evaluating the protocol of hydrogen refueling stations and suggested measures to improve safety. Hazard and operability study was performed for qualitative risk assessment, and Hy-KoRAM was used for quantitative risk assessment. Through a qualitative risk assessment, additional ventilation devices were installed, simultaneous venting of the storage container was prohibited, and the number of repeated refilling of the evaluation equipment was identified to manage the number of fillings of the container. Through quantitative risk assessment, the area around the device was set as a restricted area when evaluating the station, and measures were suggested to reduce the frequency of accidents.

• Educational Technology International
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• v.24 no.1
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• pp.1-27
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• 2023

This study aimed to examine an augmented reality-based teaching simulation in a mobile application. We examined how AR-enabled interactions affect users' perceived scenario usefulness and avatar realism. The participants were forty-six undergraduate students. We randomly grouped them into two conditions: AR and Non-interactive video groups with equal sample sizes. This study employed an experimental design approach with a one-way multivariate analysis of variance with repeated measures. The independent variable is the presence/absence of AR interaction with a mobile application. The dependent variables were avatar realism and scenario usefulness. The measures explored how the student avatar's emotional intensity in a scenario influences user perception. The results showed that participants in the AR-interaction group perceived avatar realism significantly higher than those in the non-interactive video group. Also, participants perceived the high emotional intensity scenario (aggression toward peers) to be significantly higher usefulness than the low emotional intensity scenario (classroom disruption).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.8
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• pp.294-303
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• 2017

As the elderly population increases, the prevalence of various geriatric chronic diseases and dementia diseases is also rapidly increasing; accordingly, dementia is becoming a major concern of our society. In this study, 48 elderly patients with mild cognitive impairment located in K district were selected from a group of experimental groups in one building and a control group in one building and evaluated for blood homocysteine levels and cognitive function changes after 4,8, and 12 weeks of taking vitamin supplements. The Chi-squared test, Fisher's Exact test, independent t-test, repeated measures ANOVA, contrast test, repeated measures ANCOVA, and Wilks' lambda test were utilized to analyze the data. The results revealed that the cognitive function of the experimental group was significantly higher than that of the control group at 12 weeks (p<0.05), and so, the experimental group higher than that of the control group (p<0.01), the effect of taking vitamins was significantly increased, indicating that homocysteine was decreased relative to the control group. Therefore, vitamin supplements may prevent decreases in cognitive functions and dementia among elderly patients with mild cognitive impairment.

• Korean Journal of Child Studies
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• v.15 no.2
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• pp.141-152
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• 1994

The purpose of this study was to investigate the goal and strategy differences in the Social Problem Solving (SPS) according to ages and interaction targets of children. The subjects were 48 children between the ages of 3, 4 and 5 years. Their SPS behavior was observed as it occurred naturally in free play interactions. The data were analysed by one-way ANOVA, Duncan's multiple range, repeated measures, and t-test. The results showed that there were significant goal and strategy differences in SPS behavior according to age and interaction targets of children.