• 조명전기설비학회논문지
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• 제28권8호
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• pp.62-68
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• 2014

The series connection type superconducting fault current limiter (SFCL) with added third winding, which was magnetically coupled in one iron core, was proposed. The proposed SFCL was expected to be more improved by just adding third winding into the conventional series connection type SFCL with two coils. To analyze the contribution of the third winding for the current limiting and the recovery characteristics of the SFCL, the short-circuit tests for the series connection type SFCL with the added third winding were performed together with the analysis on its electrical equivalent circuit. From the comparative analysis on the amplitude of the limited fault current and the power burden of the high-TC superconducting (HTSC) element comprising this SFCL, the improved current limiting and recovery characteristics of the series connection type SFCL using the third winding could be confirmed.

• Journal of Advanced Marine Engineering and Technology
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• 제34권6호
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• pp.887-893
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• 2010

기관실 시뮬레이터에서 3상유도전동기에 대한 모델링을 단순하게 처리하는 경우에는 왜곡된 특성에 의해 각종 전기 기계적 모의 성능 수준이 크게 저하된다. 한편, 전동기 특성을 1, 2차 측 파라미터로 구분하는 기존의 등가회로 방식들은 복잡한 실험을 거치거나 상세 기술 자료가 확보되지 않고는 현장 전동기에 대한 회로에서의 파라미터 값들을 확정하지 못한다는 점에서 정격제원 정도만 주어지는 기관실 시뮬레이터의 개발 작업 환경에서는 사용할 수가 없다. 이러한 문제의 해결을 위해 본 논문에서는 최소 파라미터에 의한 전원 직결의 2 회로정수 방식 등가회로를 제시하였으며 이로부터 정격제원에 의해 회로정수가 결정되기까지의 조건과 과정 및 관련 식들을 해석하였다. 또한 실제 전동기에 이를 적용하여 얻어지는 특성곡선들을 통해 임의의 전동기에 대한 근사특성과 실용성을 확인하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.57-58
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• 2010

This paper proposes maximum torque control of IPMSM drive using optimal current. This control method is applicable over the entire speed range which considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. This paper considers the design and implementation of novel technique of high performance speed control for IPMSM using multi-MFC and ANN controller. Also, this paper proposes maximum control of IPMSM drive using approximation method. This method is decreased the burden of digital signal process(DSP) in calculation of optimal current. This paper proposes the analysis results to verify the effectiveness of the MFC and ANN controller. Also it verifies the validity of maximum torque control of IPMSM drive with optimal current.

• International journal of advanced smart convergence
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• 제7권3호
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• pp.140-145
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• 2018

This study is based on the National Pension Research Institute's 2013 Korean Retirement and Income Study(KReIS) 5 Data for Parents and Children Care over 50 years old and analyzed the satisfaction level of life according to the characteristics of 226 people in society. The results showed that women were more satisfied with their lives than men, and when the age was lower, when they had spouses, and when they had independent economic power. As for the grandchildren caring provider, the higher the education levels, the higher the satisfaction with life. And across all areas, the grandchildren care provider showed greater satisfaction with life than the parents care provider. These results show that the burden of the parents' carers is as great as that. Suggestions based on these results are as follows. First, It is necessary to develop a health care program that can be easily accessed by family carers. Second, Direct economic support is needed, with the primary focus being on family carers. Third, services targeting parents care providers are needed. It is also necessary to form a network that can share the difficulties of parental care.

• 한국안전학회지
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• 제29권3호
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• pp.129-135
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• 2014

The number of abnormal operation procedures (AOPs) for mitigating a plant abnormal status amounts to about one hundreds for the most of 1000MWe optimized power plant (OPR1000) and it is expected that the number of AOPs would be increased to cope with an abnormal status occurred newly. However, it is not well organized for operators to select a proper AOP from alarms occurred in main control room (MCR) during a plant abnormal status. It may be a burden to operators since the selection of AOP to respond an abnormal status is authorized by operators. When multiple alarms occur in MCR, it would take more time to respond them than a single alarm. To reduce the efforts, various MCR operation support systems have been developed. The purpose of this study was to develop a multi-alarm pattern card to select an appropriate AOP effectively when multiple alarms occurs in a single upper layout (UL) of MCR. It can be applied for an operation support tool as well as an education tool.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.249-251
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• 2008

We investigated a flux-coupling type superconducting fault current(SFCL) limiter. The SFCL consisted of the primary and secondary coils, which were wound in series each other through an iron core. Superconducting unit was connected with secondary coil in parallel. The flux generated from a coil in normal operation is cancelled out by its structure and the zero resistance of the superconducting unit. In this paper. In order to compare the current limiting effects of the SFCL by applied voltage. When a lied voltage was increased, quench time was shortened Fast quench time is important component under the same fault condition because power burden of the SFCL is reduced by that of the superconducting units. The current limiting behavior of flux-coupling type SFCL was dependent upon the applied voltage.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.295-300
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• 1998

In this paper, a real time diagnostic algorithm fur estimating the impact location by loose parts is proposed. It is composed of two modules such as the alarm discrimination module (ADM) and the impact-location estimation module(IEM). ADM decides whether the detected signal that triggers the alarm is the impact signal by loose parts or the noise signal. When the decision from ADM is concluded as the impact signal, the beginning time of burst-type signal, which the impact signal has usually such a form in time domain, provides the necessary data fur IEM. IEM by use of the arrival time method estimates the impact location of loose parts. The overall results of the estimated impact location are displayed on a computer monitor by the graphical mode and numerical data composed of the impact point, and thereby a plant operator can recognize easily the status of the impact event. This algorithm can perform the diagnosis process automatically and hence the operator's burden and the possible operator's error due to lack of expert knowledge of impact signals can be reduced remarkably. In order to validate the application of this method, the test experiment with a mock-up (flat board and reactor) system is performed. The experimental results show the efficiency of this algorithm even under high level noise and potential application to Loose Part Monitoring System (LPMS) for improving diagnosis capability in nuclear power plants.

• 대한핵의학회지
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• 제37권4호
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• pp.207-218
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• 2003

Myocardial perfusion imaging has been increasingly used to provide prognostic data and guidance on the choice of appropriate management of patients with known or suspected coronary artery disease. The electrocardiogram gated myocardial SPECT program is corning into wide use with an advent of $^{99m}Tc-labeled$ tracers and an improvement of SPECT machines. The gated technique permits measurement of important cardiac prognostic indicators without any further discomforts or radiation burden in patients underwent standard myocardial perfusion SPECT. In addition, gated study significantly improves diagnostic yield by reducing the number of borderline interpretations and could find myocardial stunning and viable myocardium. Gated single photon emission computed tomography (SPECT) imaging allows the automated calculation of end-diastolic volume, end-systolic volume, ejection fraction, myocardial mass and the assessment of regional wall motion and thickening, and it have dramatically improved assessment of coronary artery disease in routine nuclear practice. This allows the simultaneous assessment of both perfusion and function within the same acquisition, and serves as a cost-effective technique for providing more diagnostic data with fewer diagnostic tests. Because the diagnostic and prognostic power derived from knowledge of left ventricular function can be added to that provided by assessing myocardial perfusion, gated SPECT imaging has rapidly gained widespread acceptance and is now used on a routine clinical basis in a growing number of laboratories, including South Korea. The gated SPECT technique for measurement of left ventricular parameters has been validated against a variety of well established techniques. In this work, overview of gated myocardial perfusion SPECT focus on functional parameters is presented.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.2
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• pp.373-376
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• 2006

Marine officers should have crisis control ability because ship operation needs not only highly specialized information, but also functional capability due to the fact that there always exist dangers at sea, which are different from those at shore. Therefore, marine officers should be trained on the related specialized information under the systematical educational system including shipboard training. Their training is also based on the strong spiritual power and physical strength through the strict training process. In order to have these vocational personalities, dormitory life training and shipboard training courses seem to be essential processes, which are required of maritime education. The introduction of automatic system into the ship as a result of the recent development of technology brings decrease of the full number of crew. Consequently, marine officers are increasingly under heavy burden, and should have more ship operation capabilities than before. Maine officers should have not only specialized information which differs from that at shore, but also vocational adaptability which can reasonably tackle with all the problems which exist on the spot and are obstacles to individual, spiritual, physical, natural, and social demands. So it is required that marine officers should have study many areas to deal with as extra curricula besides their major field of study, which are unique characteristics of the education for them. These vocational adaptabilities are based on the spiritual characteristics, such as self-developmental education, responsibility, meticulous care, attentiveness, voluntary, planning, readiness, spontaneity, accuracy, self-denial, obedience, leadership, and etc.

• 한국지능정보시스템학회:학술대회논문집
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• 한국지능정보시스템학회 2005년도 춘계학술대회
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• pp.283-291
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• 2005

The development of mobile applications is fast in recent years. However, nearly all applications are for messaging, financial, locating services based on simple interactions with mobile users because of the limited screen size, narrow network bandwidth, and low computing power. Processing an algorithm for supporting a group decision process on mobile devices becomes impossible. In this paper, we introduce the mobile-oriented simple interactive procedure for support a group decision making process. The interactive procedure is developed for multiple objective linear programming problems to help the group select a compromising solution in the mobile Internet environment. Our procedure lessens the burden of group decision makers, which is one of necessary conditions of the mobile environment. Only the partial weak order preferences of variables and objectives from group decision makers are enough for searching the best compromising solution. The methodology is designed to avoid any assumption about the shape or existence of the decision makers's utility function. For the purpose of the experimental study of the procedure, we developed a group decision support system in the mobile Internet environment, MOBIGSS　and applied to an allocation problem of investor assets.