• Korean Journal of Child Studies
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• v.38 no.2
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• pp.205-218
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• 2017

Objective: This study examined the correlation between variables influencing teacher sensitivity to infant classes in Educare Center teachers and teacher sensitivity, by classifying their personal psychological, socio-psychological, and work environment variables. Furthermore, it aimed to inquire the extent to which these variables influence teacher sensitivity. Methods: The study included 236 Educare Center teachers in charge of infant classes working in infant-caring facilities. Based on stepwise multiple regression analysis, a significance test was conducted for each variable. Results: Firstly, according to the correlations regarding teacher sensitivity to infant classes, for sensitive interaction, emotional stability showed significant positive correlation, while there were significant negative correlations with relationships with the director, colleagues,and parents; mean working hours in other places; and mean daily personal time. For insensitive interaction, there were significant negative correlations with emotional stability and mean daily break time, while there were significant positive correlations with relationships with the director, colleagues, and parents. Secondly, regarding the influences on teacher sensitivity to infant classes, for sensitive interaction, the most significant influences consisted in the relationships with colleagues and parents. On the other hand, for insensitive interaction, the most significant influences were the relationship with colleagues and emotional stability. Conclusion: Reducing interpersonal relationship stress and increasing the emotional stability of Educare Center teachers will increase their sensitivity level. Furthermore, the quality of care will be improved.

• Child Health Nursing Research
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• v.11 no.4
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• pp.415-426
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• 2005

Purpose: The purpose of this study was to identify relations among the parenting stress, maternal sensitivity to infant cues, parenting environment of first-time mothers. Method: The participants were 194 first-time mothers of babies aged 1-6 months who visited well-baby clinics in 5 hospitals. The data were collected from April 15 to June 15, 2003. Results: The parenting stress level was moderate with a mean score of 2.4(range 1-5). The parent domain and parent-child relationship domain of the parenting stress scale were significantly correlated with maternal sensitivity to infant feeding cues (r=-.178, p<.05; r=-.197, p<.01). Parenting stress was significantly correlated with childrearing environment(r=-2.19, p<.01). Parenting stress and childrearing environment were significantly different according to the educational level of the mothers and their prenatal care. Conclusions: Nursing interventions to reduce parenting stress in first-time mothers are needed to improve maternal sensitivity to infant cues and childrearing environment which foster infant development.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.27 no.2
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• pp.169-178
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• 2020

Purpose: This study examined the mediating effects of nursing professionalism on the relationship between the stress of clinical practice and compassion competence in nursing students. Methods: A correlational research design was used in this study. The participants were 120 nursing students recruited from three universities in South Korea. Data were collected using the self-reporting scales of stress of clinical practice, nursing professionalism, and compassion competence. Baron and Kenny's regression method and the Sobel test were used to analyze the mediating effects of nursing professionalism on the association between the stress of clinical practice and compassion competence. Results: The mean score for compassion competence was above average. Of the compassion competence domains, sensitivity and insights had the highest and lowest scores, respectively; there were significant mean differences in compassion competence scores according to their grade and level of satisfaction with nursing major. Compassion competence correlated negatively with the stress of clinical practice, whereas it correlated positively with nursing professionalism. In addition, nursing professionalism exerted full mediating effects on the relationship between the stress of clinical practice and compassion competence. Conclusion: The results suggested that enhancing nursing professionalism could help promote compassion competence among nursing students who experience stress in clinical practice.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.140-141
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• 2006

Most PM components are exposed to cyclic loading over long periods of time, yet, the fatigue performance is often at best characterized by a fully reversed bending strength. The effects of density, deviating loading modes, external notches or mean stresses must usually be estimated. The amount of available data is nowadays sufficient to come to fact-based estimates.

• Journal of Aerospace System Engineering
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• v.15 no.2
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• pp.16-25
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• 2021

Reliability of fatigue strength on Aircraft Composites(GFRP) Structures was assessed in this paper. Fatigue strength of GFRP was used through the existing fatigue test data with Monte Carlo method. The S_a-N_f curve of composites fatigue strength was assumed as normal distribution and reliability was analyzed using SSIT model. Fatigue stress was designed IAW ASTM F3114-15 with special safety factor of S_sf=1.2~2.0. Reliability was calculated by analytic method and FORM. Sensitivity for the effect of mean and standard deviation of fatigue strength as well as fatigue stability was evaluated. This result can be usefully applied to reliability and fatigue design for composite structures of light weight aircraft.

• Journal of the Korean Data and Information Science Society
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• v.26 no.1
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• pp.271-280
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• 2015

In this paper, the maximum likelihood estimators for parameters are derived under three step-stress accelerated life tests for Type-I hybrid censored data. The exponential distribution and the cumulative exposure model are considered based on the assumption that a log quadratic relationship exits between stress and the mean lifetime ${\theta}$. The test plan to search optimal stress change times minimizing the asymptotic variance of maximum likelihood estimators are presented. A numerical example to illustrate the proposed inferential procedures and some simulation results to investigate the sensitivity of the optimal stress change times by the guessed parameters are given.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.2
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• pp.15-21
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• 1993

This paper considers the optimal design of accelerated life test in which the stress is linearly increased. It discusses the special case when the life distribution under constant stress follows an exponential distribution and the accelerated equation satisfies the inverse power law. It is assumed that cumulative damage is linear, that is, the remaining life of test units depends only on the current cumulative fraction failed and current stress(cumulative exposure model). The optimization criterion is the asymptotic variance of the maximum likelihood estimator of the log mean life at a design stress. The optimal increasing rate is obtained to minimize the asymptotic variance. Table of sensitivity analysis is given for the prior estimators of model parameters.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.11
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• pp.831-836
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• 2010

In this paper, Plasma Enhanced Chemical Vapor Deposition (PECVD) $SiO_2$ film properties are modeled using statistical analysis and neural networks. For systemic analysis, Box-Behnken's 3 factor design of experiments (DOE) with response surface method are used. For characterization, deposited film thickness and film stress are considered as film properties and three process input factors including plasma RF power, flow rate of $N_2O$ gas, and flow rate of 5% $SiH_4$ gas contained at $N_2$ gas are considered for modeling. For film thickness characterization, regression based model showed only 0.71% of root mean squared (RMS) error. Also, for film stress model case, both regression model and neural prediction model showed acceptable RMS error. For sensitivity analysis, compare to conventional fixed mid point based analysis, proposed sensitivity analysis for entire range of interest support more process information to optimize process recipes to satisfy specific film characteristic requirements.

• The Korean Journal of Nuclear Medicine
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• v.31 no.1
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• pp.30-35
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• 1997

It has been shown that both rest and stress myocardial perfusion imagings with technetium agents can be performed on the same day using two different doses injected within few hours. The purpose of this study was to compare the two protocols (stress-rest and rest-stress) in detecting coronary artery diseases. One hundred and sixty patients (101 males, 59 females, mean age $57{\pm}9$ years) and 120 patients (79 males, 41 females, mean age $59{\pm}10$ years) underwent stress-rest myocardial perfusion SPECT and rest-stress myocardial perfusion SPECT, respectively. All of them underwent both myocardial perfusion SPECT and coronary angiography within 1 month. A coronary stenosis was considered significant when it compromised the luminal diameter by ${\geq} 50%$. The chi square test was used to compare differences in sensitivity, specificity and accuracy between the two groups. The overall sensitivity, specificity and accuracy of stress-rest protocol were 99%, 35% and 68%, respectively. Those of rest-stress protocol were 96%, 47% and 78%, respectively. There was no difference between the two protocols in identifying individual diseased coronary artery branches. Therefore, one day stress-rest and rest-stress myocardial SPECT using $^{99m}Tc$ agents were comparable and were very sensitive tests in detecting coronary artery diseases.

• Computers and Concrete
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• v.31 no.3
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• pp.253-265
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• 2023

In this research, the gene expression programming (GEP) technique was employed to provide a new model for predicting the maximum loading capacity of concrete-encased steel (CES) columns. This model was developed based on 96 CES column specimens available in the literature. The six main parameters used in the model were the compressive strength of concrete (f_c), yield stress of structural steel (f_ys), yield stress of steel rebar (f_yr), and cross-sectional areas of concrete, structural steel, and steel rebar (A_c, A_s and A_r respectively). The performance of the prediction model for the ultimate load-carrying capacity was investigated using different statistical indicators such as root mean square error (RMSE), correlation coefficient (R), mean absolute error (MAE), and relative square error (RSE), the corresponding values of which for the proposed model were 620.28, 0.99, 411.8, and 0.01, respectively. Here, the predictions of the model and those of available codes including ACI ITG, AS 3600, CSA-A23, EN 1994, JGJ 138, and NZS 3101 were compared for further model assessment. The obtained results showed that the proposed model had the highest correlation with the experimental data and the lowest error. In addition, to see if the developed model matched engineering realities and corresponded to the previously developed models, a parametric study and sensitivity analysis were carried out. The sensitivity analysis results indicated that the concrete cross-sectional area (A_c) has the greatest effect on the model, while parameter (f_yr) has a negligible effect.