• The Transactions of the Korean Institute of Electrical Engineers P
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• v.63 no.4
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• pp.241-247
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• 2014

This paper propose a variable parameter estimations of five-phase squirrel-cage induction motor(IM) for speed control system. In order to high performance control of AC motor using a field oriented control(FOC) and direct torque control(DTC) algorithm, there are required precise motor parameters for slip calculation, flux observer, controller gain, rotor position, speed estimation, and so on. We are suggest a analyzed estimation results of the motor parameters that developing five-phase squirrel-cage IM have a stator of concentrated winding for experimental of variable input power frequency. There are results of stator winding test, no-load test, locked-rotor test, variable actual load test, and estimated parameters of equivalent circuits using manufactured experimental apparatus by IEEE Standard Test Procedure for Polyphase Induction Motors and Generators 112-2004.

• The Korean Journal of Rehabilitation Nursing
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• v.12 no.2
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• pp.120-129
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• 2009

Purpose: This study was to explore elderly people's elder abuse experiences, and the relations between the abuse experiences (direct and indirect) and their level of activities of daily living, family relations and self-integrity. Method: A descriptive survey was conducted, and the participants were 108 elderly people. Data were analyzed using SPSS by descriptive statistics and t-test. Result: It was that indirect abuse experiences of the elder was higher than direct abuse experiences. In this research, the most common kind of direct elder abuse was 'psychological abuse and negligence', and the severity was low. The largest portion of indirect abuse experiences belonged to 'physical abuse and negligence', and the severity was high. The older people who had direct abuse experiences showed lowered self-integrity and serious family problems and stress. Conclusion: The experiences of elder abuse showed differences in family relations and self integrity. Hence, there should be a nursing intervention improving psycho-social factors such as self integrity and family relations, and systematic and easily available supporting organizations for victims of elder abuse.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.163-167
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• 2009

Although the domestic electric power consumption of lighting have shared 20${\sim}$30 % of the national electric power consumption, the spread of lighting control system which can reduce the electric power consumption have been insignificant. The government have set the demonstration project and given the incentive to promote the spread of lighting control system since 2008. The M&V (Measurement and Verification) methodology for lighting control system have not been set yet in our country, but the direct measurement was suggested in US. The direct measurement methodology can increase the accuracy of measurement, but it cost much money to burden a customer. This study have suggested a new M&V methodology which cost low and is simple relatively. I had measured the amount of electric consumption through both the direct measurement and the new M&V program computation, and have analyzed the deviation. The amount of electric consumption measured by the new M&V program computation have agreed with one by the direct measurement within the error range of the instrumentation in case of lab scale test, and the 4${\sim}$8 % deviation have existed in case of field evaluation.

• Journal of Power Electronics
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• v.9 no.5
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• pp.781-790
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• 2009

This paper presents an implementation of a direct active and reactive power control for a doubly fed induction generator (DFIG), which is applied to a wind generation system as an alternative to the classical field-oriented control (FOC). The FOC has a complex control structure that consists of a current controller, a power controller and frame transformations. The performance of the FOC depends highly on parameter variations of the rotor and stator resistances and the inductances. The proposed direct power control (DPC) method produces a fast and robust power response without the need of complex structure and algorithms. One drawback, however, is its high power ripple during a steady state. In this paper, active and reactive power controllers and space-vector modulation (SVM) are combined to replace hysteresis controllers used in the original DPC drive, resulting in a fixed switching frequency of the power converter. Simulation results with the FOC and DPC for a 3kW DFIG are given and discussed, and the experimental results of a test involving identical machines are presented to illustrate the feasibility of the proposed control strategy.

• Journal of Korean Academy of Nursing
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• v.36 no.2
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• pp.244-254
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• 2006

Purpose: This study was performed to analyze effects of the power and empowerment on job satisfaction and organizational commitment. This study was based on the Kanter's theory of organizational empowerment. Method: A predictive, non-experimental design was used to test the model in a sample of 688 nurses working in 7 university hospitals that have over 500 beds in Seoul, Kyunggi and Kangwon provinces. The data were collected from December, 2003 to January, 2004. It was analyzed with descriptive statistics and Pearson correlation of SPSS and with path analysis of LISREL. Result: The formal and informal power had direct effects on empowerment. Formal power also had direct effects on informal power. Empowerment had direct effects on job satisfaction and organizational commitment. Organizational commitment had direct effects on job satisfaction. There was positive effects in all of the variables. Conclusion: The positive changes show on personal behaviors and attitudes when the nurses who have formal and informal power are empowered. These findings would be important resource to nurse administrators for clinical implication.

• Korean Journal of Childcare and Education
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• v.14 no.1
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• pp.1-20
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• 2018

Objective: The purpose of this study was to examine the direct and indirect effects (through working mothers' overprotective parenting behavior) of working mothers' separation anxiety and job satisfaction on preschoolers' separation anxiety. Methods: A total of 251 working mothers with preschool-aged children participated in this study. Mothers completed a questionnaire concerning their separation anxiety, job satisfaction, overprotective parenting behavior, and preschoolers' separation anxiety. Data were analyzed using t-test, one-way ANOVAs, partial correlations and path analysis. Results: In terms of direct effects, working mothers' separation anxiety had a direct effect on preschoolers' separation anxiety. However, job satisfaction did not have a direct effect on preschoolers' separation anxiety. With respect to indirect effects, working mothers' separation anxiety indirectly influenced preschoolers' separation anxiety through their overprotective parenting behavior. However, mothers' job satisfaction did not have an indirect effect on preschoolers' separation anxiety. Conclusion/Implications: Findings from this study emphasize the importance of reducing mothers' separation anxiety in order to prevent preschoolers' separation anxiety.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.50-57
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• 2010

Various installation faults may lie in fasteners in the construction of a direct-fixation track by the top-down method. At an extreme, they may cause excessive interaction between the train and track, compromise the running safety of the train, and cause damage to the track components. Therefore, the faults need to be kept within the allowable level through an investigation of their effects on the interactions between the train and track. In this study, the vertical dynamic stiffness of fasteners in installation faults was measured based on the dynamic stiffness test by means of an experimental apparatus that was devised to feasibly reproduce gap faults. This study proposes an effective analytical model for a train-track interaction system in which most elements, except the nonlinear wheel-rail contact and some components that behave bi-linearly, exhibit linear behavior. To investigate the effect of the behavior of fasteners in gap faults in a direct-fixation track on the vehicle and track, vehicle-track interaction analyses were carried out, targeting key review parameters such as the wheel load reduction factor, vertical rail displacement, rail bending stress, and mean stress of the elastomer. From the results, it was noted that the gap faults in the concrete bearing surface of a direct-fixation track need to be limited for the sake of the long-term durability of the elastomer than for the running safety of the train or the structural safety of the track.

• Korean journal of food and cookery science
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• v.14 no.5
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• pp.482-491
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• 1998

The objectives of this study were to characterize the food service managements in university food services. In a survey involving university food service centers throughout the country, the importance, performance scores and policies for food service management were investigated. Of the total 40 institutions surveyed, 23 were run directly by the institution, eight by contract, and nine by rental. Data were analyzed by t-test, ANOVA using the SPSS program. Management system was evaluated separately for organization, human resources, finance, nutrition education, purchasing, quality control, sanitation and safety, and marketing for their relative importance, degree of performance, and policy establishment. It was found that the relative importance scored higher than the degree of performance and policy establishment. When rhe relative importance for the direct, contract and rental operations was compared, the rental operation scored the highest. Performance score of direct was the highest in direct operation. The findings of this research suggest that the university food service should be creative through systematic management, and further research is needed to evaluate various variables that influence productivity, such as employee morale, pleasant working environment, customer satisfaction, and introduction of TOM for university food services.

• Research in Community and Public Health Nursing
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• v.17 no.2
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• pp.153-165
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• 2006

Purpose: The purpose of this study was to develop and test a structural model on cardiovascular disease risk factors among male manufacturing workers. Methods: Data were collected through questionnaires and health exams from 201 workers in a local electronic company during September 2004. Data analysis was done with SAS 9.1 for descriptive statistics and PC-LISREL 8.54 for covariance structural analysis Results: The overall fit of the hypothetical model to the data was moderate, it was modified by deleting five paths. The modified model had a better fit to the data($x^2=504.23$(p<001, df: 180), $x^2/df=2.80$, GFI=.95, RMR=.07, NFI=.90, PGFI=.64). Health behaviors and psychosocial distress were found to have significant direct effects on the cardiovascular disease risk factors. Self-concept had direct effect on psychosocial distress or health behaviors. Self-concept, work environment, and work condition had direct effect on social support. Work environment had indirect effect on psychosocial distress. Social support had indirect effect on health behaviors. But work environment and work condition were found to have little direct effect on health behaviors, psychosocial distress or cardiovascular disease risk factors. Conclusion: A cardiovascular health promotion program should therefore include psycho-social factors as well as health behavioral determinants in worksites.

• Human Ecology Research
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• v.52 no.3
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• pp.213-228
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• 2014

This study examined the effects of peer relationships, depression, and aggression on bullying and victimization among boys and girls. The subjects were 364 3rd grade students (boys, 218; girls, 146) and 368 6th grade students (boys, 186; girls, 182), that is, a total of 732 students from three elementary schools. Data were collected on bullying, victimization, peer relationships (mutual friendship, mutual antipathy, and peer popularity), depression, and aggression (overt aggression and relationship aggression) from July 12, 2012 to July 13, 2012. These data were analyzed by means of a chi-squared analysis, t-test, and a logistic regression analysis. The results revealed that there were differences by sex in the case of direct bullying and victimization but no differences in the case of indirect bullying and victimization. Among boys, the factors influencing direct bullying were depression and overt aggression, and the factor influencing direct/indirect victimization was depression. Among girls, the factors influencing direct bullying were mutual antipathy relations and relational aggression, the factors influencing indirect victimization were mutual antipathy relations and peer popularity, the factor influencing indirect bullying was mutual antipathy relations, and the factor influencing indirect victimization was peer popularity. The results of this study showed that the factors influencing bullying and victimization are differences in sex. Finally, the implications and methodology for developing bullying prevention education programs were discussed.