• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 추계학술대회
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• pp.93-96
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• 2006

PEMFC(proton exchange membrane fuel cell) is most applicable to automobile in various types of fuel cell. However, to improve system dynamics and logn term Performance fuel cell is supported by auxiliary power unit forming hybrid system. The operating strategy of hybrid system influences on efficiency and stability. In this paper the proper strategies are compared each other considering power distribution and stable system operation. The chosen strategy is simulated by MATLAB simulink to forecast realization of fuel cell hybrid vehicle

• 경영과학
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• 제14권2호
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• pp.139-159
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• 1997

Recently banking industry is experiencing fundamental changes by advancement of information technology. The traditional role of branches is rapidly being replaced with new electronic service channels such as ATM. Phone and PC for they are time-saving and convenient. Automated service channel strategy of retail banks is divided into two different ways, automation and networking. Automation is mainly focused on cost reduction related to the branch operation, while networking is on expansion of customer contact points. Strategic types of banks can be defined from a matrix model shere the positioning is determined by the extent of automation and networking. The effectiveness of automated channel strategy depends on how separate strategic types show their performance. Results for deposits and productivity will be given to verify the economic performance of each strategic type.

• Journal of Power Electronics
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• 제14권6호
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• pp.1263-1271
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• 2014

A novel hysteresis PWM control strategy for synchronous buck converter is proposed. The proposed control strategy is based on ampere-second balance of the modulate capacitor, which not only offers faster transient response to meet the challenges of the power supply requirements of fast dynamic load changes, but also provides better stability and solves the compensation problem of error amplifier in the conversional voltage PWM control. Finally, the steady-state and dynamic operation of the control method is analyzed and verified by simulation and experimental results.

• 한국데이타베이스학회:학술대회논문집
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• 한국데이타베이스학회 2001년도 추계 컨퍼런스: 인터넷 비즈니스 환경에서의 디지털 컨텐츠 기술 발전 및 활용을 위한 컨퍼런스
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• pp.453-472
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• 2001

최근 들어 CRM이 확산됨에 따라 고객과의 접점에서 업무를 담당하는 콜센터의 중요성이 커지고 있으며, 정보기술이 발전함에 따라 콜센터 본연의 업무를 넘어서 콜센터에 새로운 역할이 부가되고 있다. 지금까지 콜센터에는 기계와의 커뮤니케이션에서 발생하는 거부감, 과다한 대기시간, 새로운 통신수단들로 인한 콜센터의 기능약화, 적절한 정보의 적시 사용의 어려움, 기술투자 선행작업의 미약 등의 문제점이 지적되었다. 하지만 무엇보다도 가장 큰 문제점은 명확하게 수립된 경영전략과 운영전략이 없었다는 것이다. 이에, 고객, 서비스 전략, 인적 자원, 프로세스, 정보기술 등 다섯 가지 영역으로 나누어 다른 기업과의 차별화를 달성할 수 있는 콜센터의 경영전략을 수립해야 한다. 고객의 측면에서는 만족되지 않고 있던 고객욕구를 경쟁기업보다 앞서 제공해야 하고, 서비스 전략 측면에서는 고객과의 거래비용을 줄여줄 수 있는 전략이 필요하다. 인적자원 측면에서는 보다 전문적인 서비스를 제공할 수 있는 능력을 보유한 종업원을 콜센터에 배치해야 하며, 프로세스 측면에서는 콜센터를 통해 업무창구를 일원화하는 방향으로 업무 프로세스를 리엔지니어링 해야 한다. 끝으로 정보기술 측면에서는 인터넷과 콜센터를 통합할 수 있는 방안을 모색해야 한다. 그리고 이상과 같은 경영전략 하에 구축된 콜센터의 성과를 극대화하기 위해서 필요한 8가지 운영전략을 도출하였다.

• 한국경영과학회지
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• 제14권2호
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• pp.139-139
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• 1989

Recently banking industry is experiencing fundamental changes by advancement of information technology. The traditional role of branches is rapidly being replaced with new electronic service channels such as ATM. Phone and PC for they are time-saving and convenient. Automated service channel strategy of retail banks is divided into two different ways, automation and networking. Automation is mainly focused on cost reduction related to the branch operation, while networking is on expansion of customer contact points. Strategic types of banks can be defined from a matrix model where the positioning is determined by the extent of automation and networking. The effectiveness of automated channel strategy depends on how separate strategic types show their performance. Results for deposits and productivity will be given to verify the economic performance of each strategic type.

• Journal of Power Electronics
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• 제16권2호
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• pp.769-777
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• 2016

This work focuses on current sharing between punch-through insulated gate bipolar transistors (IGBTs) connected in parallel and evaluates the mechanisms that allow overall current balancing. Two different control strategies are presented. These strategies are based on the modification of transistor gate-emitter control voltage V_GE by using an active gate driver circuit. The first strategy relies on the calculation of the average value of the current flowing through all parallel-connected IGBTs. The second strategy is proposed by the authors on the basis of a current cross reference control scheme. Finally, the simulation and experimental results of the application of the two current sharing control algorithms are presented.

• Journal of Power Electronics
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• 제11권1호
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• pp.28-36
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• 2011

In this paper, a three phase cycloconverter type high frequency AC link inverter is discussed. The configuration consists of a high frequency full-bridge inverter and a high frequency transformer followed by a three phase cycloconverter whose switch is composed of anti-series connected MOSFETs with a common source. A simple digital control strategy based on space vector modulation (SVM) and repetitive control for the cycloconverter is proposed although its input voltage is a high frequency AC pulse. The operation principle of the proposed control strategy is analyzed and the equivalent working modes during one interval are also presented. The effectiveness of the proposed control strategy is verified through Matlab/Simulink simulations and experiments on a 1.45kW prototype.

• 한국자동차공학회논문집
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• 제9권6호
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• pp.24-29
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• 2001

Adaptive valve timing control is one of the promising techniques to accomplish the optimized mixture formation and combustion depending on the load and speed, which is needed to meet the future challenges in reducing fuel consumption and exhaust emissions. The behavior and the effect of adaptive valve timing control system has been investigated by computer simulation, which simulates the gas dynamics in engines. Improved fuel economy can be achieved by reduction of pumping loss under low and mid load conditions. EIVC(Early Intake Valve Closing) strategy turns out to be superior to LIVC(Late Intake Valve Closing) strategy in reducing fuel consumption. Deterioration of combustion quality can be overcome by introducing LIVO(Late Intake Valve Opening) strategy, which increases turbulent intensity in cylinders. Furthermore, LIVO can reduce HC emission by decreasing the required amount of fuel to be injected during cold start.

• 한국자동차공학회논문집
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• 제23권2호
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• pp.239-245
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• 2015

In order to control the hybrid power system efficiently, the knowledge for the required load of the system is important. The agricultural tractor performs various farm works such as plow, rotary, and baler. When it performs rotary tillage and baler operation, the generated work load is analyzed. To analyze trend of work load, moving average technique is applied to the measurement data. Optimal control inputs for the two works are obtained from simulation using the dynamic programming. The novel fundamental control strategy for parallel hybrid tractor called Max. SOC is proposed.

• 산업공학
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• 제9권3호
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• pp.157-167
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• 1996

Due to the drastic technological innovation and introduction of various kinds, of new communication services, the structure and operation of communication networks are becoming complicated and diversified more and more. Accordingly, the necessity of flexible simulation tools which can be utilized for various performance evaluation jobs in various types of communication networks is growing. In this article, various existing simulation tools are briefly surveyed and the requirements for the simulator dedicated for the performance evaluation of communication networks are discussed. Then, a strategy to develop a simulator dedicated for the performance evaluation of communication networks is proposed. Our approach is based on the prototyping strategy, in which a relatively simple prototype structure is developed first and more functions are added whenever necessary. By following this strategy, a simulator can be developed and evolved in a timely manner at a relatively small cost.