• Journal of Korean Academy of Nursing
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• v.43 no.1
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• pp.114-122
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• 2013

Purpose: The purpose of this study was to examine burnout and job satisfaction among nurses based on Job Demand-Resource Model. Methods: A survey using a structured questionnaire was conducted with 464 hospital nurses. Analysis of data was done with both SPSS Win 17.0 for descriptive statistics and AMOS 18.0 for the structural equation model. Results: The hypothetical model yielded the following Chi-square=34.13 (p=<.001), df=6, GFI=.98, AGFI=.92, CFI=.94, RMSR=.02, NFI=.93, IFI=.94 and showed good fit indices. Workload had a direct effect on emotional exhaustion (${\beta}$=0.39), whereas supervisor support had direct effects on emotional exhaustion (${\beta}$=-0.24), depersonalization (${\beta}$=-0.11), and low personal accomplishment (${\beta}$=-0.22). Emotional exhaustion (${\beta}$=-0.42), depersonalization (${\beta}$=-0.11) and low personal accomplishment (${\beta}$=-0.36) had significant direct effects on job satisfaction. Conclusion: The results suggest that nurses' workload should be decreased and supervisor's support should be increased in order to retain nurses. Further study with a longitudinal design is necessary.

• Child Health Nursing Research
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• v.18 no.4
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• pp.222-230
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• 2012

Purpose: The purpose of this study was to identify the effect of family stressors, family strains, general family values, family values for hospitalized children and family hardiness on family adaptation based upon McCubbin's family resilience model for families of hospitalized children in China. Methods: A survey using a self-report questionnaire was conducted with 330 hospitalized children's parents. Six instruments were used in this model. The data were analyzed using SPSS WIN 19.0 and AMOS 19.0 program. Results: Family strain had a significant negative direct effect, general family values and family hardiness had a significant positive direct effect, and family values for hospitalized children had a significant positive direct effect and indirect effect on family adaptation of hospitalized children. Conclusion: In this study McCubbin's resilience model and resiliency factors were identified. According to the finding of this study nursing interventions to reduce family stress, enhance family hardiness and consolidate general family values and family values for hospitalized children can help to increase family adaptation in families of hospitalized children. Therefore, the significance of this study is that the results can be used to develop family nursing intervention programs based on family resilience to strengthen family adaptation in families of hospitalized children.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.5 no.4
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• pp.19-30
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• 2002

The stability of slope using root-pile like to the reinforcements is affected by the interaction behavior mechanism of soil-reinforcements. Through the studying on the interaction in joint of its, therefore, the control roles can be find out in installed slope. In study, the stress level ratio based on the insert angle of installed reinforcements in soil used to numerical analysis, which was results from the duty direct shear test in Lab. The maximum shear strain variation on the reinforcements was observed at insert angle, which was approximately similar to the calculated angle based on the equation proposed by the Jewell. The elasto-plastic joint model on the contact area of soil-reinforcements was presumed, the reinforced soil assumed non-linear elastic model and the reinforcements supposed elastic model, respectively. The finite element analysis of assumed models was performed. The shear strain variation of non-reinforced state obtained by the FEM analysis including elasto-plastic joint elements were shown the rationality of general limit equilibrium analysis for the slope failure mode on driving zone and resistance zone, which based on the stress level step according to failure ratio. Through the variation of shear strain for the variation of inserting angle of reinforcements, the different mechanism on the bending and the shear resistance of reinforcements was shown fair possibility.

• Journal of Power Electronics
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• v.18 no.1
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• pp.1-10
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• 2018

Recently, the nine-switch inverter has been proposed as a dual output inverter. To date, studies on the control strategies for NSIs have been mostly combined with their application. However, in this paper, a mathematical model and control strategy for nine-switch inverters has been proposed in view of the topology. A switching function model and equivalent circuit model of a nine-switch inverter have been built in ${\alpha}{\beta}$ coordinates. Then, a novel current observer with an improved integrator is proposed based on the switching function model, and a direct power control strategy is proposed. No current sensors are used in the proposed strategy, and only two voltage sensors are employed. The performance of the proposed control method is verified by simulation and experimental results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2001.11a
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• pp.181-185
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• 2001

This paper presents a digitally speed sensorless control system for induction motor with direct torque control (DTC). The drive is based on Mode1 Reference Adaptive System (MRAS) using state observer as a reference model fat flux estimation. The system are closed loop stator flux and torque observer for wide speed range that inputs are currents and voltages sensing of motor terminal, model reference adaptive control (MRAS) with rotor flux linkages for the speed turning aignal at low speed range, two hysteresis controllers. The Proposed system is verified through simulation.

• 제어로봇시스템학회:학술대회논문집
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• 1990.10b
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• pp.872-877
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• 1990

Robustness of a model refernece direct adaptive pole placement control for not necessarily minimum phase systems is studied subject to unmodeled dynamics and bounded disturbances. The adaptive control scheme involves two estimators for the system and the controller parameter estimation, respectively. The robustness is obtaind under some weak assumptions and by using both a normalized least-squares algorithm with dead zone and an appropriate nonlinear feedback.

• East Asian Economic Review
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• v.16 no.1
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• pp.25-66
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• 2012

The paper analyzes the effect of expected future demand on the investment decisions of multinational enterprises. In particular, I explore the issue of the timing of switching between exporting and FDI in the host developing country and explicitly incorporate the firm's attitude toward risk in the model. The model demonstrates that the optimal time for switching to FDI depends on the expected future demand and the degree of its uncertainty.

• Journal of Industrial Technology
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• v.18
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• pp.233-240
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• 1998

In this study, ride sensitivity analysis of train with non-linear suspension elements is performed. Non-linear characteristics of springs and dampers for primary and secondary suspensions of a train is parameterized. Equation of motion of the train model is derived, and using the direct differentiation method, sensitivity equations are obtained. For a nominal ride quality performance index, sensitivity analysis with respect to various design parameters regarding non-linear suspension parameters is carried out.

• Transactions of the Korean Society of Automotive Engineers
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• v.5 no.1
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• pp.87-100
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• 1997

The ability of turbulence model to accurately describe the complex characteristics of the flow field and the fuel spray is of great importance in the optimum design of diesel engine. The numerical simulations of the flow field and the spray characteristics within the combustion chamber of direct injection model entgine are performed to examine the applicability of turbulence model. The turbulence models used are the RNG $\varepsilon$ model and the modified $\varepsilon$ model which included the compressibility effect due to the compression/expansion of the charges. In this study, the predicted results in the quiescent condition of direct injection model engine show reasonable trends comparing with the experimental data of spray characteristics, i. e., spray tip penetration, spray tip velocity. The results of eddy viscosity obtained using the $\varepsilon$ model in the spray region is significantly larger than that obtained using the RNG $\varepsilon$ model. The application of the RNG model seems to have some potential for the simulations of the spray characteristics, e. g., spray tip penetration, spray tip velocity, droplets distribution over the $\varepsilon$ model.

• The Korean Nurse
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• v.31 no.5
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• pp.72-87
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• 1992

This study was designed to develop and lest a structural model for paternal adaplation and family stress in the families with the handicapped children. A hypothetical model was constructed on the basis of family stress theory developed by McCubbin etc. The model included 6 theoretical concepts and 11 paths. For the purpose of the model testing, empirical data were collected from May to August, 1992. The subject of the study constituted 190 mothers whose children admitted in the five special schools and one privale institutes in Seoul and Choong Nam. In data analysis, SPSS PC+ and PC-LISREL 7.13 computer program were utilized for descriptive and covariance structure analysis. The results of lhe study were as follows. (1) Hypothetical model showed a good fit to the empirical data [Chi-square = 21.19 (df = 7, P = o. 003), Goodness of Fit Index=O.986, Adjusted Goodness of Fit Indes=0.946, Root Mean Square lesidual=0.048), Non Normed Fit Index = 0.80, Normed Fit Index=0.91]. (2) The results of Hypothesis testing indicated: 1) Social support(${\gamma}_11=.238$, T=2.352), Family Functioning(${\gamma}_12=.729$, T=5.957) had direct effects on situational definition. 2) life event stress(${\gamma}_23=.284$, T=5.220) had direct effects on the effect of the handicapped chid on the family. 3) Family functioning(${\gamma}_32=-.239$, T= -3.370) had direct effects on paternal adapation. From the above results, the significance of this study can be delineated as follows : The construction and testing of the comprehensive model seem to be the first trial in Korea. The model was supported by empirical dala. Thus it was suggested that model could be adequately applied to framily nusing care with the handicapped.