• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.3
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• pp.325-331
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• 2018

This paper deals with the dynamical analysis of a vessel that leads to capsize in regular beam seas. The complete investigation of nonlinear behaviors includes sub-harmonic motion, bifurcation, and chaos under variations of control parameters. The vessel rolling motions can exhibit various undesirable nonlinear phenomena. We have employed a linear-plus-cubic type damping term (LPCD) in a nonlinear rolling equation. Using the fourth order Runge-Kutta algorithm with the phase portraits, various dynamical behaviors (limit cycles, bifurcations, and chaos) are presented in beam seas. On increasing the value of control parameter ${\Omega}$, chaotic behavior interspersed with intermittent periodic windows are clearly observed in the numerical simulations. The chaotic region is widely spread according to system parameter ${\Omega}$ in the range of 0.1 to 0.9. When the value of the control parameter is increased beyond the chaotic region, periodic solutions are dominant in the range of frequency ratio ${\Omega}=1.01{\sim}1.6$. In addition, one more important feature is that different types of stable harmonic motions such as periodicity of 2T, 3T, 4T and 5T exist in the range of ${\Omega}=0.34{\sim}0.83$.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.24 no.3
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• pp.219-229
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• 2017

Purpose: The aim of this study was to examine the relationship between handwashing knowledge and handwashing compliance in nursing students and to identify the moderation and mediation effects of self-efficacy and perceived behavioral control on the relationship. Methods: The participants were 172 nursing college students who completed the self-report measures. Data were analyzed using t-test, ANOVA, and Pearson correlation coefficient, Multiple regression analysis was used to test moderation and mediation effects. Results: The score for knowledge of handwashing was higher in participants who had completed fundamentals of nursing practicum (t=-6.54, p<.001) and the score for compliance with handwashing was higher in participants who had completed clinical practicum (t=-3.81, p<.001) or fundamentals of nursing practicum (t=-5.97, p<.001). Self-efficacy showed a significant moderation effect (z=2.21, p=.027) but not a mediation effect while perceived behavioral control had a significant mediation effect but not a moderation effect on the relationship between knowledge of handwashing and compliance. Conclusion: Findings indicate that clinical practicum and fundamentals of nursing practicum were helpful to nursing students in acquiring knowledge and in practicing proper handwashing technique. These findings suggest that continuing and repetitive education programs on handwashing need to be enhanced and strategies to strengthen self-efficacy and perceived behavioral control need to be included in education programs.

• Child Health Nursing Research
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• v.24 no.4
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• pp.364-372
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• 2018

Purpose: The aim of this study was to test whether maternal uncertainty and the general characteristics of mothers and children influenced maternal coping. Methods: In this cross-sectional study, 190 mothers whose children had been admitted to the pediatric ward of a general hospital completed self-report questionnaires during their children's hospitalization. The questionnaires assessed the general characteristics of the mothers and children, maternal uncertainty, and maternal coping. Multiple regression analysis was used to test the research model. Results: In the multivariable model, help from one's spouse (t=3.10, p=.002), religion (t=2.68, p=.008), overall ambiguity (t=2.64, p=.009), and family income (t=2.33, p=.021) were associated with higher coping scores. Conclusion: This research model presents possible guidelines for pediatric nurses to provide comprehensive and accurate information on children's illnesses and treatments for mothers of children hospitalized in general hospitals. In particular, nurses should pay more attention to mothers who are not receiving help from their spouses, are not religious, and have a low family income.

• Child Health Nursing Research
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• v.24 no.4
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• pp.373-382
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• 2018

Purpose: This study aimed to compare the quality of nursing care as perceived by registered nurses and mothers of hospitalized children in South Korea. Methods: This was a descriptive study that recruited 70 mothers of hospitalized children and 70 nurses in pediatric units in university hospitals as participants. The quality of pediatric nursing care was measured using importance and performance scores for 19 items describing various elements of nursing care. The collected data were analyzed using descriptive statistics and the independent t-test. Results: The hospitalized children mothers'mean importance scores were significantly higher than those of the nurses (t=2.94, p=.004). However, there were no significant differences in the mean performance scores of nurses and mothers (t=0.91, p=.363) or between nurses'and mothers'perceptions of quality of nursing care, with the exception of a significant difference for the quality of explanations (t=2.78, p=.006). The quality of explanations was assessed more positively by nurses than by mothers. Conclusion: This study suggests that when developing strategies to improve the quality of nursing care in pediatric wards, ensuring that pediatric nurses provide detailed explanations should be considered as a way to improve the quality of nursing care in pediatric units.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.272-276
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• 2005

Food wastewater derived from three-stages methane fermentation system showed high concentrations of sCOD, T-N and $NH_{3}-N$. To treat the organic wastewater, the optimal operating conditions for high efficiency $UV/TiO_{2}$ photocotalytic system have been investigated. In the first process, wastewater was pre-treated with $FeCl_{3}. The optimum pH and concentration for coagulation were 4.0 and 2000 mg/L, respectively. Through this process, 52.6% of $COD_{cr}$ was removed. The second process was $UV/TiO_{2}$ photocatalytic reaction. The optimum conditions for the operation of $UV/TiO_{2}$ photocatalytic system developed in this lab have been studied. In this process, CODcr was removed from 2890 to 184 mg/L and T-N was removed from 2496 to 914 for 24 hours, respectively.

• Journal of environmental and Sanitary engineering
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• v.11 no.1
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• pp.83-91
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• 1996

It is not too much to say that the territorial inhabitants' concerns are wholly c concentrated on the environmental preservation-problem and development-problem in Korea given effect to the local self-government system. At a time like this I was studied the effect on nutrients removal through lighting period in aerobic high rate pond and we know that waste stabilization pond method is the most economical and energy saving wastewater treatment technology than others. At the results which was studied through operating the reactor-l artifically main-tained at a temperature, $25^{\circ}C$, a light intensity, 3000lux, and a lighting period, 24hrs and the reactor-2 artifically maintained at a tern야rature, $25^{\circ}C$ and a light intensity 3000lux, and a lighting period period, 12hrs, It has appeared for 24hrs.-lighting period -reactor-1 to be prior to the reactor-2. The attained results are that 1. reactor-1 is prior to reactor-2 on oxygen-generation 2. reactor-1 is prior to reactor-2 on algal production 3. COD removal efficiency, 90.76%, T-N removal efficiency, 80%, T-P removal e efficiency, 74.47 % in reactor-2, in reactor-1 COD removal efficiency, 94.85 %, T-N removal efficiency, 98.07%, T-P removal efficiency, 72.13% are, so the treatment efficiency of reactor-1 is more excellent than things of reactor-2 4. it appeared that the detention time is 8, 9days.

• Journal of Korean Society on Water Environment
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• v.25 no.5
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• pp.727-734
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• 2009

This study was carried out to evaluate the high rate biological reactor such as lab scale reactor before the application in site, and to get the basic data for possibility using liquid fertilizer with the effluent from biological reactor when the centrifugal machine was applied. The total volume of this reactor in 6 L, in composted of anoxic reactor (2 L), aerobic reactor (2 L), and nitification reactor (2 L). BOD removal efficiency rates when centrifugal machine was applied after effluent from biological reactor are over than 95%. This biological reactor was required post process to satisfy the effluent standards, and was need centrifugal machine to control the washout of microbes in the reactor. T-N removal efficiency rate in HRT 24 hr with centrifugation is 80.0%, and it is desirable to operate less than $1.3kgN/m^3{\cdot}d$ for 70% of T-N removal efficiency rate. T-P removal efficiency rate in HRT 24 hr is 68.2%, and become higher 71.3% after centrifugation. Considering in the 28.6% T-N removal efficiency rate, the nitrogen contents of the effluent from reactor is 0.34% to satisfy the liquid fertilizer.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.24 no.2
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• pp.128-137
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• 2017

Purpose: This study was conducted to investigate the effects of core basic nursing education using cellular phone video recordings on self-confidence in performance, achievement, and practice satisfaction. Methods: The research design was a nonequivalent control group modified and non-synchronized design. The participants were assigned to either the experimental (n=60) or control group (n=67). During one semester, the experimental group received training for 10 selected core basic nursing skills using cellular phone video recording. The control group, also for one semester, received training with traditional practices. Self-confidence in performance and practice satisfaction were measured using a questionnaire, and achievement was evaluated by professors at the conclusion of the semester. Collected data were analyzed using t-test and Pearson correlation coefficients. Results: Self-confidence in performance increased significantly after training in the experimental group (t=7.94, p<.001). The experimental group showed significantly higher self-confidence in performance (t=2.39, p=.018) and achievement (t=2.40, p=.018) compared to the control group. However, the difference in practice satisfaction was not statistically significant. Conclusion: The results indicate that cellular phone video recording is effective in improving self-confidence in performance and achievement of core basic nursing skills.

• Journal of Oriental Neuropsychiatry
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• v.24 no.spc1
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• pp.55-62
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• 2013

Objectives : We will discuss the differences on EEG results of Post-traumatic embitterment disorder (PTED) and Major depressive disorder (MDD). Methods : We measured EEG on 21 sites (Fp1, Fpz, Fp2, F7, F3, Fz, F4, F8, T3, C3, Cz, C4, T4, T5, P3, Pz, P4, T6, O1, Oz, O2) of PTED and MDD. Then, we compared the results. Results : There is a significant result of a beta band between PTED and MDD. Conclusions : We became aware of the differences on EEG results of PTED and MDD. This can be used as the basis of diagnosis.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.24 no.1
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• pp.39-50
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• 2017

Purpose: The purpose of this study was to identify the effects simulation-based education combined team-based learning (SBE combined TBL) compared to simulation-based education (SBE) on undergraduate nursing students. Methods: A non-equivalent control group design with pre-and posttest measures was used. The participants in the study were 181 students. The SBE combined TBL group consisted of 84 senior students in 2013, and the SBE group consisted of 97 seniors in 2014. Collected data were analyzed using chi-square, independent t-test and ANCOVA with the statistical package SPSS 22.0 for Windows. Results: There was a significant improvement in communication skills, nursing performance confidence, team efficacy, and team performance scores in the SBE combined TBL group compared to the SBE group (t=2.45, p=.015; F=4.30, p=.040; t=3.06, p=.003; t=8.77, p<.001). However, there was no statistically significant difference in self-directed learning between the groups. Conclusion: SBE combined TBL compared to SBE is an effective teaching and learning method to enhance various positive educational outcomes for nursing students. Therefore, we suggest that future studies investigate the development of an integrated course in which team-based learning is applied to theoretical sessions and simulation-based training.