• Structural Engineering and Mechanics
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• v.29 no.3
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• pp.289-300
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• 2008

The use of metric trial functions to represent the real stress field in what is called the unsymmetric finite element formulation is an effective way to improve predictions from distorted finite elements. This approach works surprisingly well because the use of parametric functions for the test functions satisfies the continuity conditions while the use of metric (Cartesian) shape functions for the trial functions attempts to ensure that the stress representation during finite element computation can retrieve in a best-fit manner, the actual variation of stress in the metric space. However, the issue of how to handle situations where there is locking along with mesh distortion has never been addressed. In this paper, we show that the use of a consistent definition of the constrained strain field in the metric space can ensure a lock-free solution even when there is mesh distortion. The three-noded Timoshenko beam element is used to illustrate the principles. Some significant conclusions are drawn regarding the optimal strategy for finite element modelling where distortion effects and field-consistency requirements have to be reconciled simultaneously.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.4
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• pp.243-251
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• 2009

Refrigerant mixtures provide an opportunity to adjust their properties to fit design criteria and a possibility to create new blends that can improve heat transfer characteristics. Therefore, mixture of $CO_2$ and propane is chosen which may be a promising refrigerant and has good environmental compatibility. This paper presents measured heat transfer coefficient data during evaporation process of $CO_2$/propane mixtures flowing upward in vertical smooth and. micro-fin tubes. Smooth and micro-fin tubes with outer diameters of 5 mm and length of 1.44in were selected as test tubes. The tests were conducted at mass fluxes of 212 to $656kg/m^{2}s$, inlet temperatures of -10 to $30^{\circ}C$, heat fluxes of 15 to $60\;kW/m^2$ and for several compositions (75/25, 50/50, 25/75 wt%). Among $CO_2$/propane refrigerant mixtures, the heat transfer characteristics are much better than that of any compositions when the composition is 75/25 (wt%).

• Journal of the Korean Society of Clothing and Textiles
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• v.45 no.4
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• pp.598-611
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• 2021

The purpose of this study was to investigate the necessary functions and areas of improvement in bras worn by patients during the initial three-month recovery period after a breast augmentation procedure, and a functional bra that fits properly was designed. In order to analyze the necessary functions, a bra was designed after relevant discussions with medical staff and patients who underwent breast augmentation surgeries and considering the advice from bra designers and clothing and textile experts. This bra was designed to protect the surgical scars and minimize the compression by inserting a nonwoven fabric into the shoulder and front parts. In addition, it was designed in a way that could fit the individual breast volume by using a mesh material partially on the upper side of the molded cups. Underwires that could support the breasts were inserted, and a detachable wire was used to suit the patient's needs and the diagnosis by the medical staff. As the bra designed in this study received excellent scores during the evaluation by research subjects and experts, it can be used for designing the prototype of a functional bra.

• Journal of the Korean Society of School Health
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• v.32 no.1
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• pp.41-49
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• 2019

Purpose: The purpose of the this study was to examine the mediating effect of resilience on the relationship between social capital - family, school, and community - and self-rated health in adolescents. Methods: The study is a secondary data analysis based on a cross-sectional design, using the data of 2016 Korean Children and Youth Panel Survey (KCYPS). The study analyzed the data of 2,001 adolescents by descriptive analysis, t-test, ANOVA, Pearson's correlation coefficients and structural equation modeling, using the SPSS and AMOS program. Results: The model's fit was adequate ($x^2/df=4.51$, CFI=.98, RMSEA=.04, SRMR=.02). The adolescents' social capital - family, school and community - had direct effects on their self-rated health. Resilience was found to play a partially mediating role in accounting for self-rated health. Conclusion: Resilience partially mediated the relationship between social capital and self-rated health in adolescents. Based on the results of this study, nursing strategies to build and strengthen social capital at the family, school and community level and to promote resilience are needed to improve the health of adolescents.

• Journal of Advanced Research in Ocean Engineering
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• v.4 no.4
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• pp.185-194
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• 2018

In this study, the extreme sloshing pressure was predicted using various statistical models: three-parameter Weibull distribution, generalized Pareto distribution, generalized extreme value distribution, and three-parameter log-logistic distribution. The estimation of sloshing impact pressure is important in design of liquid cargo tank in severe sea state. In order to get the extreme values of local impact pressures, a lot of model tests have been carried out and statistical analysis has been performed. Three-parameter Weibull distribution and generalized Pareto distribution are widely used as the statistical analysis method in sloshing phenomenon, but generalized extreme value distribution and three-parameter log-logistic distribution are added in this study. Additionally, statistical distributions are fitted to peak pressure data using three different parameter estimation methods. The data were obtained from a three-dimensional sloshing model text conducted at Seoul National University. The loading conditions were 20%, 50%, and 95% of tank height, and the analysis was performed based on the measured impact pressure on four significant panels with large sloshing impacts. These fittings were compared by observing probability of exceedance diagrams and probability plot correlation coefficient test for goodness-of-fit.

• Journal of Korean Academy of Nursing
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• v.49 no.1
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• pp.80-91
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• 2019

Purpose: This study attempted to develop a scale that measures the level of patients' recognition of the nurses' care, based on Watson's caring theory, and confirmed its reliability and validity. Methods: The items were developed through a literature review and an expert content validity test. The questionnaires were administered to 285 inpatients of internal medicine and surgical units at two general hospitals. Construct validity was tested using exploratory and confirmatory factor analysis, and reliability was tested using Cronbach's alpha. Results: This process resulted in a preliminary scale composed of 34 items; We used item analysis and five exploratory factor analyses, and consequently selected 14 items composed of three factors (respect, genuineness, and relationality). The confirmatory factor analysis verified the model fit and convergent and discriminant validity of the final items; criterion validity was confirmed with the positive correlation with the measurement scale of the patient-perceived quality of nursing. The overall scale reliability had a Cronbach's alpha of .92, which indicated internal consistency and reliability. Conclusion: The developed scale showed content, construct, and criterion validity, and reliability, as well as convergent validity for each item and discriminant validity between the factors. This makes it suitable for use in a diverse range of future studies on nurse communication using structural equation models.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.45-46
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• 2014

In this paper, measurement methods for the characteristics of antennas for indoor digital TV (DTV), having 75-ohm port impedance, are introduced. Reference impedance of typical radio frequency (or microwave) systems and measurement equipments is 50 ohm. However, the reference impedance of antennas for indoor DTV is 75 ohm, and the characteristics of the antennas cannot be measured directly using the measurement equipments. Measurement methods, using test equipments with reference impedance of 50 ohm, for the characteristics(impedance, radiation patterns, and gains) of antennas designed to fit for 75 ohm port are introduced.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.944-946
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• 2014

Localization of a sensor network node using machine learning has been recently studied. It is easy for Support vector machines algorithm to implement in high level language enabling parallelism. In this paper, we realized Support vector machine using python language and built a sensor network cluster with 5 Pi's. We also established a Hadoop software framework to employ MapReduce mechanism. We modified the existing Support vector machine algorithm to fit into the distributed hadoop architecture system for localization of a sensor node. In our experiment, we implemented the test sensor network with a variety of parameters and examined based on proficiency, resource evaluation, and processing time.

• Journal of Korean Academy of Nursing
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• v.49 no.3
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• pp.241-253
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• 2019

Purpose: This study aimed to develop and test a model of the happiness of mothers with young children based on the stress-coping-adaptation model of Lazarus and Folkman. Methods: The data collection period was from May to July 2016. A self-report questionnaire was used to collect data from 210 mothers with children under 5 years of age living in Seoul, Gyeonggi, and Gangwon provinces. The exogenous variable was parenting stress, and the endogenous variables were parenting alliance, depression, optimism, ways of coping, and happiness. Data from 201 questionnaires were analyzed using the SPSS 22.0 and AMOS 20.0 programs. Data analyses included descriptive statistics, factor analysis, and structural equation modeling. Results: The final modified model showed a reasonable fit to the data, and out of 25 paths, 13 were statistically significant. This model explained 78.4% of the variance in the happiness of mothers with young children and confirmed that depression, optimism, parenting alliance, and social support-focused coping have a direct effect on the subject's happiness. Parenting stress also influenced happiness through parenting alliance, depression, and optimism. Conclusion: In order to bolster the happiness of mothers with young children, positive psychological interventions that can minimize psychological vulnerabilities, such as depression, and that can enhance their strengths, such as optimism, may serve as effective ways of coping with and adapting to stress.

• East Asian Journal of Business Economics (EAJBE)
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• v.9 no.3
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• pp.57-69
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• 2021

Purpose - The purpose of this research is to test the impact of social connectedness and team psychological safety on the relationship between transformational leadership and employee performance (job performance and practiced creativity), and moderating role of usage frequency of SNS. Research design, data, and methodology - A total of 299 questionnaires, completed by Chinese employees, were analyzed using SPSS 22 and AMOS 22. For the assessment of goodness of fit of the models, TLI, CFI, RMSEA indices were used. Result -The empirical results are as follows. First, social connectedness had a mediating effect in the relationship between transformational leadership and job performance, practiced creativity. Second, team psychological safety had a mediating effect in the relationship between transformational leadership and social connectedness, job performance, practiced creativity. Finally, the moderating effect of frequency of employee SNS usage were not significant. Conclusion -This study analyzes the mediating role of employee social connectedness and team psychological safety on the relationship between transformational leadership and job performance, practiced creativity, which is helpful for the expansion of related theories and provides practical implications for effective human resource management.