• 간호행정학회지
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• 제20권4호
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• pp.426-436
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• 2014

Purpose: This study was conducted to identify factors that affect nursing performance; Those factors are personal characteristics, sub-categories of empowerment and job satisfaction of clinical nurses. Methods: Data were collected from November 24, 2012 to March 11, 2013, and participants were 451 hospital nurses in 6 hospitals. Descriptive statistics, t-test, one-way ANOVA, Pearson correlation coefficient, and stepwise multiple regression were used for data analysis. Results: Nurses who were older, married, highly educated, in the position of charge nurse, and with longer clinical careers showed relatively higher empowerment, higher job satisfaction, and higher nursing performance than others. Also, there were strong correlations between nursing performance and empowerment (r=.576)/job satisfaction (r=.617). Factors predicted nursing performance were relationship with coworkers (${\beta}=.398$), duty (${\beta}=.181$), promotion system (${\beta}=.134$), and turnover intention (${\beta}=-.109$). Factors predicting job satisfaction were competency of empowerment (${\beta}=.249$), and clinical career (${\beta}=.151$). These 6 factors explained 55.2% of the variance in nursing performance (F=93.37, <.001). Conclusion: Regarding human resource management, relationship with co-workers is a changeable factor. Therefore nursing organizations should apply these factors in human resource management to enhance nursing performance and achieve organizational goals.

• Human Ecology Research
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• 제56권3호
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• pp.263-282
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• 2018

This study is used to understand the characteristics of home economics teachers that could to help develop personal development in home economics teacher and home economics education. The questionnaire survey was conducted on 150 home economics teachers who belong to either the home economics teachers' study association or Korean home economics education essociation. The survey was processed with frequency analysis, standard deviations, factor analysis, independent sample t-test, and reliability analysis using SPSS 12.0 depending on the contents of the research. The study results are as follows. First, for home economics teachers' conscious teaching, they build their own identities as experts, and have a vocation and sense of duty for their job. The culture of research and investigation community to study education and to maintain collaborative relationships with teachers of home economics teachers' associations has evolved. Second, home economics teachers have the ability to analyze and manage students' demands in order to perform teaching activities, and understand individual student characteristics. They understand new study trends and curriculum, develop sources for class, use appropriate teaching and learning theories, and create students' reflective activities. In addition, they grow their learning ability as specialist and study in self-oriented ways.

• 한국정보통신학회논문지
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• 제9권8호
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• pp.1722-1729
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• 2005

본 연구에서는 OpenGL 프로그램으로 4족 보행로봇인 TITAN-VIII의 가상로봇을 설계한 후, 실제로봇의 관절각도, 본체 자세각을 가상로봇에 입력하고 벡터 회전과 평행이동을 이용하여 보행 중 본체를 수평으로 유지하는 제어를 10[ms]마다 행하였다. 디딤율 $\beta$를 0,5로 일정하게 하고, 주기가 1.5, 2.0, 3.0[sec]일 때 한주기당 이동거리를 0.2, 0.3[m]로 변경하여 좌우요동보행을 시키면서 가상로봇의 ZMP, 실제로봇의 ZMP 무게중심의 이동경로를 구하고 발바닥 좌표 변화와의 관계를 비교 분석하였다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1995년도 VTS and IBS 95 The Korean Institute of Navigation 1995년도
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• pp.125-152
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• 1995

An Integrated Bridge System (IBS) is not an officially defined term, but a concept of which integrates on a consol at bridge the primary functions of stand-alone navigational aids and communication instruments or of stand-alone units which are integrated i.e. ARPA ECDIS It aims to enable officers on navigational watch to perform their duty without impairing proper lookout. IBS has been taking shape through a rapid development of navigation and communication systems in relation with bridge configuration bridge work station and one man bridge operation system. IBS related matters have been considered for years and is on the agenda of the International Maritime Organization(IMO) for its technical details and safety aspect of possible one-man watchkeeping at night. However IMO has made it clear that human element should be the key factor in considering IBS and single watchkeeping issue. In the development of IBS ergonomic element and human psychological aspect have been more emphasized than technical requirements. This paper refers to documents presented to the IMO and its progress made in various IMO technical meetings on the development of IBS which is perceived as an effective aid to proper bridge lookout and those standards adopted by classification societies on the composition of workstation at bridge in order to identify the international trend on regulating required equipment function of workstation of IBS the regulatory review process and technical recommendations related thereto.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제53권2호
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• pp.114-122
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• 2004

This paper presents a novel single-stage active-clamp type high frequency resonant inverter. The proposed topology is integrated full-bridge boost rectifier as power factor corrector and active-clamp type high frequency resonant inverter into a single-stage. The input stage of the full-bridge boost rectifier works in discontinuous conduction mode(DCM) with constant duty cycle and variable switching frequency. So that a boost converter makes the line current follow naturally the sinusoidal line voltage waveform. By adding additional active-clamp circuit to conventional class-E high frequency resonant inverter, main switch of inverter part operates not only at Zero-Voltage-Switching mode but also reduces the switching voltage stress of main switch. Simulation results have demonstrated the feasibility of the proposed high frequency resonant inverter. Characteristics values based on characteristics estimation through circuit analysis is given as basis data in design procedure. Also, experimental results are presented to verify theoretical discussion. This proposed inverter will be able to be practically used as a power supply in the fields of induction heating applications, fluorescent lamp and DC-DC converter etc.

• Journal of Power Electronics
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• 제15권1호
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• pp.31-38
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• 2015

In this paper, a buck-boost type battery charger is developed for charging battery set with a lower voltage. This battery charger is configured by a rectifier circuit, an integrated boost/buck power converter and a switched capacitors circuit. A boost power converter and a buck power converter sharing a common power electronic switch are integrated to form the integrated boost/buck power converter. By controlling the common power electronic switch, the battery charger performs a hybrid constant-current/constant-voltage charging method and gets a high input power factor. Accordingly, both the power circuit and the control circuit of the developed battery charger are simplified. The switched capacitors circuit is applied to be the output of the boost converter and the input of the buck converter. The switched capacitors circuit can change its voltage according to the utility voltage so as to reduce the step-up voltage gain of the boost converter when the utility voltage is small. Hence, the power efficiency of a buck-boost type battery charger can be improved. Moreover, the step-down voltage gain of the buck power converter is reduced to increase the controllable range of the duty ratio for the common power electronic switch. A prototype is developed and tested to verify the performance of the proposed battery charger.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.182-184
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• 2007

본 논문에서는 2단 AC/DC 컨버터와 단일단 AC/DC 컨버터가 가지고 있는 단점들을 개선 할 수 있는 새로운 준 단일 전력단 컨버터를 제안한다. DC/DC 단으로는 동적 특성이 좋은 LLC 컨버터를 채용하여 별도의 제어기 없이 고정 주파수 및 고정 Duty(50%) 발생기에 의해 Open Loop로 구동 시킴으로써 저가격화 및 고효율화를 획득 할 수 있다. 또한 역률개선단은 Boost 컨버터를 채용하고 간단한 제어기 1개를 사용하여 역률 개선과 동시에 DC/DC 단의 최종출력을 제어한다. 기존 2단 PFC 컨버터와는 다르게 PFC 링크전압을 Feedback 하지 않고 DC/DC 단의 최종 출력을 Feedback 하여 제어한다. 제안된 회로의 우수성 검증을 위해 600W급 시작품을 이용한 실험 결과를 제시한다.

• Journal of Electrical Engineering and Technology
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• 제9권2호
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• pp.589-599
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• 2014

On the basis of the traditional ZSI (Z-source inverter), this paper presents a ESL-${\Gamma}$-ZSI, which uses a unique ${\Gamma}$-shaped impedance network and an extended SL network for boosting its output voltage in addition to their usual voltage-buck behavior. The inverter can increase the boost factor through adjusting shoot-through duty ratio and increasing the number of inductors. Capacitor voltage stress of ESL-${\Gamma}$-ZSI is a constant when 1>D>0, and ESL-${\Gamma}$-ZSI has small inductor current stress. The working principle of ESL-${\Gamma}$-ZSI and comparison with the classical ZSI and SL- ZSI are analyzed in detail. The power loss comparison between ESL-${\Gamma}$-ZSI and Cuk converter is analyzed detailedly. Simulation and experimental results are given to demonstrate the operation features of the inverter.

• 한국산학기술학회논문지
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• 제8권1호
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• pp.10-17
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• 2007

자동차 미끄럼방지 장치의 최적 제어를 위해서는 유압 모듈레이터 특히, 솔레노이드 밸브에 대한 정확한 동특성 해석이 필요하다. 그러나, 현재까지 진행된 대부분의 연구들은 솔레노이드 밸브 자체만을 고려하였기 때문에 실제 자동차 미끄럼방지 장치에 제한적으로 적용되었다. 본 연구에서는 유압 모듈레이터에 작용하는 압력을 고려한 솔레노이드 밸브의 동특성 해석을 위하여 실험과 이론 해석을 실시하였다. 작동 압력이 솔레노이드 밸브의 동특성에 끼치는 영향을 정량적으로 해석하였고 설계인자를 변화시키면서 성능향상 방안을 제안하였다. 따라서, 본 연구에서 수행한 솔레노이드 밸브 동특성 해석결과는 자동차 미끄럼방지 장치의 최적 제어 기준으로 활용할 수 있을 것이다.

• Journal of Power Electronics
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• 제18권6호
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• pp.1819-1829
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• 2018

A three-phase, three-switch, and three-level boost-type PWM rectifier (Vienna rectifier) is proposed as an active front-end power factor correction (PFC) rectifier for telecom loads. The proposed active front-end PFC rectifier system is modeled by the switching cycle average model. The relation between duty ratios and DC link capacitor voltages is derived in terms of the system input currents. Furthermore, the feasible switching states are identified and applied to the proposed system to reduce the switching stress and DC ripples. A detailed equivalent circuit analysis of the proposed front-end PFC rectifier is conducted, and its performance is verified through simulations in MATLAB. Simulation results are verified using an experimental setup of an active front-end PFC rectifier that was developed in the laboratory. Simulation and experimental results demonstrate the improved power quality parameters that are in accordance with the IEEE and IEC standards.