• Proceedings of the KIEE Conference
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• summer
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• pp.1352-1354
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• 2004

The accurate analysis on railway traction power system should be carried out a load forecast preferentially. Commonly, it has been performed through Train Performance Simulator (TPS). In the study focused on velocity or location of train, however, the electric power consumption have been computed by converting mechanical power according to given velocity. Therefore, this paper presents a development of a mathematical model for electric load. The proposed load model is expressed as polynomial to reflect the influence of variance of train speed, that is, the model expresses the power as a function of train speed. in this study, method of the least squares method is used to find each coefficient and field test is performed to acquire data, electric power and speed of train in commercial running line.

• Macromolecular Research
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• v.16 no.4
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• pp.314-319
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• 2008

An image analysis processing method for the measurement of nanofiber diameter was developed. For the analysis, scanning electron microscopy (SEM) images of electrospun fiber were prepared and applied to the individual measurement of the fiber diameter by using the developed and the traditional manual methods. Both methods provided a similar fiber distribution. The fiber average diameters were similar but the variance of the new method was larger than that of the manual method. The average diameters from the two methods exhibited a linear relationship with a high coefficient. The developed method can be used as a practical tool to estimate the fiber diameter of the electro spun web.

• Proceedings of the Korea Water Resources Association Conference
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• 2002.05b
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• pp.1027-1033
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• 2002

The solute transport in a two-dimensional heterogeneous porous medium is numerically studied by using a random walk particle tracking (RWPT) method. Lognormally isotropic hydraulic conductivity fields are generated by using the turning band methods with mean zero and four different values of standard deviation. The numerical transport experiments are carried out to investigate the large time and spatial effects of the variable pore velocity field on solute plumes. The behavior of the solute plume through numerical simulations is presented in terms of longitudinal and transverse spatial moments: displacement of center-of-mass, plume spread variance and skewness coefficient. It was observed that the dispersive behavior of the solute plume is strongly affected by the degree of heterogeneity in the flow domain.

• Korean Journal of Adult Nursing
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• v.22 no.6
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• pp.606-614
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• 2010

Purpose: The purpose of this study was to identify the predictors of Organizational Citizenship Behavior (OCB) among hospital nurses. Methods: Participants in this study were 231 nurses from two hospitals. The self-reported questionnaire was used to assess the level of self-efficacy, social support and OCB. The data were analyzed using descriptive statistics, Pearson's correlation coefficient, t-test, ANOVA and multiple regression. Results: The mean score of OCB was 4.82, self-efficacy was 4.65, and social support was 4.56. The OCB was statistically significant according to position (t=-1.97, p=.049). The OCB was positively correlated with self-efficacy (r=.558, p<.001) and social support (r=.245, p<.001). The self-efficacy and social support explained 33.0% of the variance for OCB. Conclusion: The findings suggest that developing programs to improve self-efficacy and social support might be useful. Furthermore, more studies are needed to explore variables that influence nurses' Organizational Citizenship Behavior.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.179-180
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• 2015

The variety of organic and inorganic pollutants are introduced to coastal sediment and making highly contaminated due to rapid development of industralization and economic development. Numerous contaminants are release into marine sediment and it significantly affect marine aquatic environment. In the present study stated the optimize the biostimulant ball (BSB) in coastal sedimentand stabilse the heavy metals present in the sediment. The effective variables like BSB size, distance and month variables on Cu stabilization was determined by using Response surface methodology(RSM). The analysis of variance (ANOVA) and coefficient determination (R2) of Cu reduction 0.9610 and maximum stabilisation was obtained in 3cm ball size and 5.5cm distance and 4 month interval time. This result revealed that the BSB in effective for Cu reduction in coastal sediment.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.1
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• pp.52-58
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• 1998

The spray characteristics of air-assisted fuel injection and its effects on the engine combustion was investigated in this study. The atomization characteristics of a Bosch fuel injector inserted into the air-assist adapter were measured using particle motion analysis system. Droplet size decreased with air supplied and fine spray with below $60\mu\textrm{m}$ of SMD was acquired under the conditions of air-assist pressure over 0.5bar. The lean combustion performance of a 1.8L DOHC engine equipped with air-assist adapters was tested on the dynamometer. When the assistant air pressure is 1.0bar, lean limit recorded the highest value, and CO, HC emissions were decreased at the pressure over 1.0bar.

• Proceedings of the Safety Management and Science Conference
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• 2007.11a
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• pp.255-261
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• 2007

Nowadays obesity has been become a serious social issue. Many researches are trying to find the root cause of obesity. Obesity causes various kinds of disease and safety accidents in work places. Thus, the main objective of this study is to analyze obesity index of citizens in Seoul which is a metropolis of Korea and a densely populated district. In order to analyze a detailed somatotype of citizens, age groups are divided into 30-34 years, 35-39 years, 40-49 years, and 50-59 years according to gender respectively. The result of this study can be applied to the comfortable and appropriate design for workers.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.20 no.4
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• pp.438-448
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• 2013

Purpose: The purpose of this study was to investigate factors influencing clinical competence in nursing students. Method: The participants were 125 nursing students and data were collected from October 8 to December 18, 2010 using questionnaires with. Collected data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient and stepwise multiple regression. Results: There were significant correlations for creativity, problem-solving ability, self-directed learning ability, and clinical competence. The factor influencing clinical competence the most was creativity, followed by problem-solving ability, self-directed learning ability, and grade point average score. The regression model explained 37% of variance in clinical competence. Conclusion: The results indicate that for improvement in the clinical competence of nursing students, it is necessary to develop strategies and education programs to enhance creativity, problem-solving ability, and self-directed learning ability.

• Journal of Korean Academy of Nursing
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• v.34 no.5
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• pp.751-759
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• 2004

Purpose: The aim of this study was to design and evaluate a scale for measuring the attitudes toward condom use in sexual relationships. Method: A questionnaire was administered to 631 college students using a convenience sampling method. The psychometric properties (reliability and validity) were evaluated. Result: As a result of the item analysis, 16 items were selected and the internal consistency alpha coefficient was .88. Results indicated that the condom attitude scale is composed of three factors: Interruption of sexual pleasure; Protection; and Image. The three factors accounted for 59.54% of the variance in the total scale. Also, condom attitude was statistically significant (t=7.389, p=.000) between consistent condom users and inconsistent users. Conclusion: The results demonstrate that condom attitudes are multidimensional, and the reliability and validity of the scale was supported.

• Journal of the Korean Society of School Health
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• v.29 no.1
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• pp.33-41
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• 2016

Purpose: The purpose of this study was to examine relationships between optimism, coping and peer relations on mental wellbeing in adolescents, and to identify contributing factors on their mental wellbeing. Methods: A total of 132 students recruited from two middle schools. Data were analyzed using descriptive statistics, t-test, ANOVA, and Pearson's correlation coefficient, and multiple regression. Results: Adolescents' mental wellbeing was $4.23{\pm}0.84$. Their mental wellbeing was significantly influenced by optimism (${\beta}=.44$), peer relational skills (${\beta}=.21$), and active coping (${\beta}=.20$), explained 49.1% of the total variance. Conclusion: Considering the results of this study, optimism enhancement program for promoting adolescents' mental wellbeing should be builded. In addition, active coping skills and peer relational skills acquisition program need to be developed.