• Industrial Engineering and Management Systems
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• 제15권1호
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• pp.1-10
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• 2016

This paper presents a fast sequencing algorithm for a mixed model assembly line with multiple workstations which minimize the total utility work and idle time. We compare the proposed algorithms with another heuristic, the Tsai-based heuristic, for a sequencing problem that minimizes the total utility works. Numerical experiments are used to evaluate the performance and effectiveness of the proposed algorithm. The Tsai-based heuristic performs best in terms of utility work, but the fast sequencing algorithm performs well for both utility work and idle time. However, the computational complexity of the fast sequencing algorithm is O (KN) while the Tsai-based algorithm is O (KNlogN). Actual computational time of the fast sequencing heuristic is 2-6 times faster than that of the Tsai-based heuristic.

• 통상정보연구
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• 제5권2호
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• pp.3-17
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• 2003

This paper examined a e-Business utility of on-line shopping mall firms. Based on the literature review and cases study, the following results were found. First, in e-business policy, it was found that partnership between government and market are very important to e-business utility. Second, e-CRM of on-line shopping mall firms should be considered web site design based on commodity, cafe based on experience and information shares, and transaction confirm service. Third, B2C e-commerce model should be contained firm-specific force, customer oriented force, social force, and technology force.

• 전기학회논문지P
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• 제54권3호
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• pp.111-118
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• 2005

Since the residential load is an AC load and the output of solar cell is DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell. In case of driving to interact with utility line, in order to operate at unity power factor, converter must provide the sinusoidal wave current and voltage with same phase of utility line. Since output of solar cell is greatly fluctuated by insolation, it is necessary that the operation of solar cell output in the range of the vicinity of maximum power point. In this paper, DC/AC converter is three phase PWM converter with smoothing reactor. And then, feed-forward control used to obtain a superior characteristic for current control and digital PLL circuit used to detect the phase of utility line.

• Spatial Information Research
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• 제5권1호
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• pp.115-131
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• 1997

지하매설물은 지방자치단체, 통신공사, 전력공사, 도시가스회사, 지역난방공사 등 관리주체가 다양하며, 서로 다른 기본도 사용에 따른 중복투자발생, 관리부서별 다양한 도면 및 대장자료의 산재, 다양한 관리기관별 업무협조체제의 부재로 인해 통합된 정보부재 등의 문제를 안고 있다. 선진외국에서 GIS를 이용하여 지하매설물을 체계적으로 관리하고, 도시안전관리에도 기여함을 고려할 때, 지하매설물의 효율적 관리방안으로서 GIS 도입에 대한 연구가 절실함을 느낀다. 본 연구에서는 첫째 지하매설물 관리기관별 지하매설물 관리실태를 파악하고 둘째 서울시 지하매설물 관련기관에서 사용할 수 있는 확장성있는 데이터베이스 표준안을 작성하였으며 셋째 지하매설물 데이터베이스 구축에 있어 탐사에 의한 방법과 기존의 각 관리기관에서 보유하고 있는 도면을 이용하는 방법에 대한 가능성 검증 및 기존도면을 이용하여 데이터베이스를 구축하는 경우의 입력절차를 제안하고, 넷째 데이터베이스 구축 후 유지관리를 위한 방안에 대한 대안을 제시하였다.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 추계학술대회 논문집
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• pp.279-285
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• 2007

Since the residential load is an AC load and the output of solar cell is a DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell. In case of driving to interact with utility line, in order to operate at unity power factor, converter must provide the sinusoidal wave current and voltage with same phase of utility line. Since output of solar cell is greatly fluctuated by insolation, it is necessary that the operation of solar cell output in the range of the vicinity of maximum power point. In this paper, DC/AC converter is three phase PWM converter with smoothing reactor. And then, feedforward control used to obtain a superior characteristic for current control and digital PLL circuit used to detect the phase of utility line.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.361-363
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• 1996

The output of solar cell should be operated in the maximum power point, since it is greatly fluctuated by insolation and temperature. Also, since the output of solar cell is a DC power, it needs the inverter to interact with utility line. In this paper, we made composed of PV system with a chopper that control the maximum power point and the inverter that drive to the high power factor and low harmonic by use of defected and compensated utility line voltage for synchronous phase with utility line.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.288-291
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• 2007

Since the residential load is an AC load and the output of solar cell is a DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell. In case of driving to interact with utility line, in order to operate at unity power factor, converter must provide the sinusoidal wave current and voltage with same phase of utility line. Since output of solar cell is greatly fluctuated by insolation, it is necessary that the operation of solar cell output in the range of the vicinity of maximum power point. In this paper, DC/AC converter is three phase PWM converter with smoothing reactor. And then, feedforward control used to obtain a superior characteristic for current control and digital PLL circuit used to detect the phase of utility line.

• 대한전기학회논문지
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• 제41권4호
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• pp.369-378
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• 1992

This paper proposes a utility parallel processing inverter system, which consists of a voltage source PWM inverter, isolation transformer and a reactor linking the inverter to utility line. This system realizes following functions : (1) voltage phase frequency and amplitude synchronization between inverter and utility line at stand-alone mode. (2) current phase synchronization between inverter and load at parallel mode. Therefore, despite sudden increase in load current over setting point at stand-alone mode, inverter system can be transferred into parallel mode immediately without transient current. Furthermore, high frequency(18KHz) PWM control and sinusoidal filtering improve the inverter output waveform by eliminating high order harmonic components as well as low order. As a switching device, IGBT is used for high frequency switching and large current capacity.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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• pp.516-518
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• 2005

This paper presents a distance protection algorithm a lied to the linked line for interconnecting wind farm with the utility. The capacity of wind farm is lower than utility system and its fault current level is very low. When a high resistance fault occurs in the linked line, it is difficult to detect accurate fault distance because of reactance effect. By using the characteristic of equivalent source impedance of induction generator which is compensated by capacitor bank and characteristic of the capacity of wind farm, this paper proposes improved distance protection algorithm applied to the linked line. A series of PSCAD/EMTDC simulation results have shown effectiveness of the proposed algorithm.

• 디지털융복합연구
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• 제10권8호
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• pp.53-61
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• 2012

본 연구는 온라인 게임의 지속적 이용의도에 영향을 미치는 선행요인들을 살펴보았다. 온라인 설문조사를 통하여 가설을 검증한 결과, 캐릭터와의 일체감을 나타내는 원격현존감과 몰입이 게임의 가치에 영향을 미치며, 이 가치는 다시 게임의 지속적 이용의도와 게이머들간 정보공유에 영향을 미치는 것으로 나타났다. 가치의 선행요인인 몰입에 영향을 미치는 요인으로 게임 플레이 방식, 도전감이 영향을 미치는 것으로 나타났으나, 예상과는 달리 보상은 몰입에 영향을 주지 않는 것으로 나타났다. 가치의 다른 선행요인으로서 원격현존감은 게임 상에서의 정치시스템과 스토리텔링에 의해 영향을 받는 것으로 나타났다.