• 한국통신학회논문지
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• 제38C권7호
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• pp.563-572
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• 2013

본 논문에서는, 00:00~00:30까지 온라인 영업일자변경 작업 등으로, 일시적으로 중단되는 금융권 온라인 계정계 업무에 대하여, 고객원장의 복제보정 적용으로 서비스가 가능토록하며, 배치작업은 별도의 배치서버에서 수행하고, 원장 업데이트는 Center Cut 또는 온라인 서버로 전송해서 처리된다. 따라서, 온라인 업무를 포함한 모든 금융전산업무의 시뮬레이션 결과, 단 1초도 중단 없이, 각 계정 과목별 온라인 원장의 중요한 시점정보인 00:00분 (전영업일자 원장)에 대하여 배치원장과 백업원장을 안전하게 확보하였다.

• 가정과삶의질연구
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• 제21권1호
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• pp.49-60
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• 2003

The purpose of this study is to analyze expenditure on children's private, after-school education, perceptional need for private education, and budget planning pattern for the expenditure of education applying survey data, and to investigate current situation to Identify solving planning for digital age. taking on-line educational service system and internet financial planning for children's educational expenditure into account. Under the purposes, this study especially focused on the condition of on-line educational service system and the merits as well as problems of the system, the need for household financial planning for children's education, and the condition or nature of internet financial planning system, in terms of providing market information and of suggesting policy implications.

• 대한전기학회논문지:전력기술부문A
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• 제53권12호
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• pp.670-677
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• 2004

The Conventional approach for estimating the locations of transmission line shunt faults has been to measure the apparent impedance to the fault from a line terminal and to convert the reactive component of the impedance to line length. But, these methods do not adequately address the problems associated with the fault location on distribution systems. This thesis presents a technique that estimates the location of shunt fault on a radial distribution system that has several single and multiphase laterals. Tapped loads and non-homogenity of the distribution system are take into account. The developed technique, which can handle shunt faults was tested to evaluate its suitability. Results from computer simulation of faults on a model of a 25KV distribution lines like real system are presented. The results approved that the proposed technique works well for estimating the locations of the distribution line shunt faults.

• 대한안전경영과학회지
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• 제5권2호
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• pp.145-154
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• 2003

Recently, many companies want to accept and operate ERP (Enterprise Resource Planning) system in their fields ERP does not only include business, but also include finance, account, trade, personnel and BPR(Business Process Reengineering). Especially, it is necessary to have ERP system for companies which have lots of external business such as trade and communication sector. And then, in this paper, I will think about OLTP (On-Line Transaction Processing) system for operating ERP system and improve its defects that can operate more effective sales, circulation, demand plan. But it is regrettable that I can not make a comparative analysis with other systems because the ERP system is still on the introductory stage for the company studies and the benefits have not been realized yet. Another limitation of this research is its narrow scope of study in which only the raw material inventory system for a single company is covered. In the future, however, ERP system would be adopted by many corporations, which would help us to launch a comparative study on the results of ERP system implementation as a future direction of research.

• 대한전기학회논문지
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• 제36권6호
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• pp.381-389
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• 1987

This paper presents a method for optimal load shedding in preserving a system security following abnormal condition as well as a sudden major supply outage. The method takes account of static characteristic of generators control and voltage and system frequency characteristic of loads. The optimization problem is solved by a gradient technique to get the maximal effect by the least quantity of load shedding considering line overloads as well as voltage disturbances and system frequency. The method is illustrated on a 8-bus system. It has been found that the use of the proposed algorithm for model systems alleviate the line overload more efficiently than the former method. It is believed that this method will be useful in security studies and operational planning.

• 제어로봇시스템학회논문지
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• 제9권10호
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• pp.782-788
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• 2003

Making deicing countermeasure plan against snow accretion on power line is a very complicated problem, which should take into account both the possibility of accidents due to snow accretion on power line and the stable operation of power system. As knowledge engineering can be a good solution to this field of problems, a prototype expert system to assist power system operators in forecasting snow accretion on power lines and making a list of all the feasible and effective deicing countermeasures has been developed. The system has been remodelled into a fuzzy expert system by adopting fuzzy rulebase and fuzzy inference method to systematically process the fuzziness included in the heuristic knowledges. Simulation results based on the past snow accretion accident data show that the proposed system is very promising.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.296-298
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• 2001

This paper represents protective management system for transmission line involving the UPFC(Unified Power Flow Controller) device, which is the most vigorous component of FACTS. The presence of the UPFC significantly affects the line parameters of transmission system, which are also influenced by the distance relay setting. Moreover, depending on the UPFC location and its parameters, zones of setting the distance relay will be changed. Therefore, established protective system should be taken into account the variable injected voltage of the UPFC and constructed data base system.

• Journal of Power Electronics
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• 제15권6호
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• pp.1628-1639
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• 2015

Line-interactive uninterruptible power supply (UPS) systems are good candidates for providing energy storage within a microgrid. In this paper, a control scheme for a line-interactive UPS system applied in a low-voltage microgrid is presented. It is based on the Q-w and P-E droop control to achieve a seamless transition between grid-connected and stand-alone operation modes. Moreover, a new model for designing the controllers is built in the dq-frame based on the instantaneous power definition. The new-built model takes into account the dynamic performance of the output impedance of the inverter in the dq-frame and can be evaluated in the time domain. Compared to the traditional model based on the instantaneous power definition, the new-built model is more accurate to describe the dynamic performance of the system. Simulation and experimental results obtained with a microgrid consisting of two 40-kW line-interactive UPS systems are given to validate the control strategy of the line-active UPS system and the accuracy of the new-built model.

• KIEE International Transactions on Power Engineering
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• 제4A권2호
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• pp.84-90
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• 2004

This paper presents a new method for choosing the best line for transmission system expansion planning considering the highest reliability level of the transmission system. Conventional methodologies for transmission system expansion planning have been mainly focused on economics, which is the minimization of construction costs. However, quantitative evaluation of transmission system reliability is important because successful operation and planning of an electric power system under the deregulated electricity market depends on transmission system reliability management. Therefore, it is expected that the development of methodology for choosing the best lines considering the highest transmission system reliability level while taking into account uncertainties of transmission system equipment is useful for the future. The characteristics and effectiveness of the proposed methodology are illustrated by the case study using a MRBTS.

• 전기의세계
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• 제28권1호
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• pp.43-52
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• 1979

Recently, interest in multivalued(MV) logic system has been increased, despites the apparent difficulties for practical application. This is because of the many advantages of the MV compared with the 2-valued logic systems, such as; (a) higher speed of arithmetical operation on account of the smaller number of digits required for a given data, (b) better utilization of data transmission channels on account of the higher information contents per line, (c) potentially higher density of information storage. This paper describes a MV switching theory and experimental MV logic elements based on current-mode logic technique. These elements tried were a 3-stable pulse generator, a ternary AND, a ternary OR, a MT circuit and a ternary inverter. Tristable flops which are indispensable for constituting a ternary shift register are synthesized using these gates. A BCD to TCD decoder, and vice versa, are proposed by using a ternary inverter and some binary gates. Thus, the feasibility of a large scale MV digital system has been demonstrate.