• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.75-78
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• 2007

The structural methodology in designing a transmission tower have been performed to assume a simple truss behavior. But there're quite differences between a simple truss behavior and a real one. A suitable explanation for a structural stability can be expressed as a semi-rigid connection instead of the assumed hinged connection. This study proposes an alternative structural analysis modelling strategy for the transmission tower design. Proposed element models are truss element model, beam element model, and combined beam-truss element model. The static finite element analysis shows that there's a moment distribution between a mainpost member and the other bracing member.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1997년도 추계학술대회발표논문집; 홍익대학교, 서울; 1 Nov. 1997
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• pp.193-196
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• 1997

In this paper we consider a Bayesian theoretic approach to periodic incomplete preventive maintenance with minimal repair at failure. We assume that the system failure rate is increasing as the frequency of PM increases and that the system is replaced at the K-th PM under this maintenance strategy. The optimal policies which minimize the expected cost rates are discussed. We seek the optimal periodic PM interval x and replacement time K under a Weibull failure intensity. Assuming suitable prior distribution for the Weibull parameters, we derive the posterior distribution incorporating failure data and obtain the updated optimal replacement strategies.

• 한국유통학회:학술대회논문집
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• 한국유통학회 2005년도 동계학술대회 발표논문집
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• pp.327-353
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• 2005

본 연구는 동북아 물류활성화를 위해 지정학적으로 환황해권의 유리한 위치와 우리나라의 경제중심지인 수도권을 배후로 하고 있는 평택항을 중심으로 한 경기지역의 물류네트워크 전략에 대한 연구이다. 본 연구에서는 국내 수출입 컨테이너물동량의 유통채널의 분석과 물류네트워크 방식의 검토 및 사례분석을 통해 경기지역의 특성에 맞는 물류네트워크 방식에 대해 연구하였다. 따라서 하드웨어 개념인 각 거점별 물류시설간의 물류채널인 네트워크 구성방안에 대해 언급하였고 여기서 대권역과 소권역으로 분류하여 2단계 혼합물류네트워크 방식을 소개하였으며, 이러한 각 거점물류시설간의 효율적인 운영을 위해 가장 중요하다고 사료되어지는 물류정보시스템의 구축방안에 대해 언급하였다.

• 수산해양교육연구
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• 제26권4호
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• pp.760-768
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• 2014

Yet logistics base in China has a refrigerated storage facilities installed areas, the number of those is very limited and is generally insufficient. According to these especial points, a new construction cold chain logistics network design strategy is required from how to use the existing refrigerated warehouses to new issue. For example, however refrigerated storage facility is supplied, can it satisfy all demand of this area? Then does it have optimized location of this area? If future demand expansion, adding that already other refrigerated storage facilities matter? Or, add another refrigerated facilities, optimum cold chain established a network matter? So on. Above problems can be occurred. In order to solve facing many of these issues of distribution network, northeast area in China has been selected as a subject, and we designed a new cold chain distribution network.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.277-280
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• 2002

With significant development of power electronics technology, the proliferation of nonlinear loads such as static power converters has deteriorated power quality in power transmission and distribution systems. Notably, voltage harmonics resulting from current harmonics produced by the nonlinear loads have become a serious problem in many countries. There are already a lot of PV power generation systems installed in building systems whose harmonics are the worst object for distribution systems as a utility interactive system and also it tends to spread out continuously. In this paper, the authors propose a multy-function inverter control strategy which puts a shunt active filter function to the power inverter of the PV power generation system established on a building system. The effectiveness of the proposed system is demonstrated through the simulation of hypothetical power system using PSCAD/EMTDC.

• 전기학회논문지
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• 제61권7호
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• pp.966-973
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• 2012

In microgrid demonstration site, distributed generations can make bidirectional power flows on the system. If an accident occurs, the fault current from the inverter based distributed generation is small. However, the conventional protection scheme in distribution network is designed to operate at high fault current. This means that the traditional protection of distribution network is no longer applicable and new protection methods must be developed. In this paper, for two cases, algorithms for protection coordination of demonstration site is proposed and verified through PSCAD/EMTDC simulation. In first case, protection devices are assumed to have the abilities of directional relaying and communication. In second case, protection devices do not have those abilities. Proposed protection coordination algorithms detect the fault locations and protect the microgrid fairly well.

• 경영과정보연구
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• 제34권3호
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• pp.141-160
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• 2015

USNs, NFC, M2M에서 확장된 사물인터넷은 새로운 컨버전스 기술로써 주요 이슈가 되고 있다. 사물인터넷은 인간의 개입 없이 센싱 네트워크와 프로세싱 간에 공동으로 지능형 연결을 구축할 수 있는 네트워킹으로 정의된다. 본 연구의 목적은 사물인터넷이 물류 산업에 기여하는 것과 미래 사회에 대한 변화를 예측하는 것이다. 실제 세계 시장의 리더가 되기 위해서는 물류 산업의 사물인터넷 개발을 더 많이 요구하고 새로운 서비스 창조와 차별화된 시장을 위한 전략이 필요하다. 그러므로 물류 산업의 세계 리더가 되기 위해서는 다른 것들 보다 사물인터넷 표준화, 사생활 보호, 보안문제 등이 중요하다는 것을 알 수 있다. 따라서, 본 연구에서는 물류 산업의 사물인터넷 개발을 위해서 고객편의를 높이도록 노력하고 소비자의 수요를 잘 고려하여 차별화된 사물인터넷 물류 서비스를 제공할 수 있게 하여야 한다는 것을 보여주고자 함이 본 논문의 목적이며, 이를 위해 국내외 사례를 분석하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 B
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• pp.1169-1170
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• 2006

Grid connected PV(Photovoltic) generation systems are becoming and actual and general. The power output of PV system is directly affected by the weather conditions. And when AC power supply is needed, power conversion by an inverter and a MPPT control are necessary. The PV power generation system can be treated to a harmonics source for the power distribution system. So, the PV system combined the function of active filter system can be useful applied in power distribution system. AF(Active Filters) intended for harmonic solutions are expending their functions from harmonic compensation of nonlinear loads into harmonic isolation between utilities and consumer. With the test analysis of the proposed control strategy of PV-AF system, the outcome of the test shows the stability and effectiveness of the proposed PV-AF system. The various capability of AF has been proved in previous research and usage. In this paper, authors present a DSP controlled PV-AF system for power conditioning in three-phase industrial or commercial power systems and verify it through experimental results.

• 유통과학연구
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• 제4권2호
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• pp.65-80
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• 2006

본 연구는 백화점 상황에서 지각된 품질, 고객가치 차원(실용적 가치와 쾌락적 가치) 및 고객만족간의 관계에 영향을 미치는 관계를 조사하고자 한다. 즉, 지각된 품질은 실용적 가치와 쾌락적 가치 및 고객만족에 어떤 영향을 미치는지 그리고 실용적 가치와 쾌락적 가치가 고객만족에 어떤 영향을 미치는지 조사하였다. 본 연구의 결과는 지각된 품질은 실용적 가치, 쾌락적 가치 및 고객만족에 그리고 실용적 가치와 쾌락적 가치는 고객만족에 통계적으로 유의한 양의 관계가 있는 것으로 나타났다. 이러한 결과를 바탕으로 백화점 소매상을 위한 시사점을 제공하였으며, 또한 연구의 한계점과 미래연구방향을 제시하였다.

• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.11-18
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• 2017

In order to maintain customer voltages within the allowable limit($220{\pm}13V$) as much as possible, tap operation strategy of SVR(Step Voltage Regulator) which is located in primary feeder, is widely used for voltage control in the utilities. However, SVR in nature has operation characteristic of the delay time ranging from 30 to 150 sec, and then the compensation of BESS (Battery Energy Storage System) during the delay time is being required because the customer voltages in distribution system may violate the allowable limit during the delay time of SVR. Furthermore, interconnection of PV(Photovoltaic) system could make a difficultly to keep customer voltage within the allowable limit. Therefore, this paper presents an optimal coordination operation algorithm between BESS and SVR based on a conventional LDC (Line Drop Compensation) method which is decided by stochastic approach. Through the modeling of SVR and BESS using the PSCAD/EMTDC, it is confirmed that customer voltages in distribution system can be maintained within the allowable limit.