• Journal of Power Electronics
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• 제19권3호
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• pp.637-644
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• 2019

Wireless power transfer (WPT) technology with various transfer mechanisms such as inductive coupling, magnetic resonance and capacitive coupling is being widely researched. Until now, power transfer efficiency (PTE) and power transfer capability (PTC) have been the primary concerns for designing and developing WPT systems. Therefore, a lot of studies have been documented to improve PTE and PTC. However, power consumption in the standby mode, also defined as the no-load mode, has been rarely studied. Recently, since the number of WPT products has been gradually increasing, it is necessary to develop techniques for reducing the standby power consumption of WPT systems. This paper investigates the standby power consumption of commercial WPT products. Moreover, a standby power reduction technique for WPT systems via magnetic resonance coupling (MRC) with a parallel resonance type resonator is proposed. To achieve a further standby power reduction, the voltage control of an AC/DC travel adapter is also adopted. The operational principles and characteristics are described and verified with simulation and experimental results. The proposed method greatly reduces the standby power consumption of a WPT system via MRC from 2.03 W to 0.19 W.

• 융합신호처리학회논문지
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• 제16권3호
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• pp.115-121
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• 2015

가정 및 사무실의 전기/전자 기기가 내부 혹은 외부로부터 주 기능 수행을 위한 명령을 기다리고 있는 상태에서 소모되는 대기전력을 차단할 수 있는 장치를 저가로 개발하였다. 대기전력을 줄이기 위한 노력이 선진국들뿐만 아니라 국제적 차원에서 경주되고 있다. 우리나라도 가구당 전자/전기기기 보유대수가 증가되는 추세에 따른 대기전력이 점차 증가하고 있어 전기 에너지 낭비의 큰 요인이 되고 있다. 기존의 대기전력 차단장치는 그 장치 자체의 소비전력이 크고, 구조가 복잡하여 사용 의미를 퇴색시키는 문제점을 안고 있다. 본 논문에서는 기존 제품의 이러한 문제점을 보완시키고 대기전력을 완전히 차단하는 저가형 대기전력 차단장치를 제안한다. 그리고 제안한 대기전력 차단장치를 누전차단기와 콘센트에 적용하여 회로를 설계 및 구현하고 실험을 통하여 그 우수성을 확인하였다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2007년도 추계학술대회 및 정기총회
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• pp.341-356
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• 2007

본 연구는 우리나라 이동전화고객의 서비스 전환(번호이동)에 영향을 미치는 요인에 대한 실증 분석을 다루고 있다. 실증 분석을 위해서 본 연구에서는 이동전화 번호이동제가 도입된 2004년 1사분기부터 2007년 2사분기까지 총 14개 분기의 시계열 자료를 활용하였다. 종속변수로는 이동통신 3사의 분기별 번호이동자수를 이용하였으며 설명변수로는 이동통신사의 가입자 유치비용 및 전환비용과 더불어 수요특성을 감안한 대기수요효과, 추세효과, 구조변화효과 등을 고려하였다 분석 결과 각 사업자별 번호이동 유입자수에 영향을 미치는 요인이 상이함을 확인할 수 있었다 구체적으로 SKT로 이동해오는 고객 수는 SKT의 가입자 유치비용, KTF에서 오는 대기수요 등이 유의한 영향을 미치는 것으로 나타났으며, KTF로 이동해오는 고객 수는 번호이동고객이 느끼는 전환비용, SKT로부터의 대기수요 등의 영향을 받는 것으로 나타났다. LGT에는 LGT의 유치비용과 추세의 영향을 크게 받는 것으로 나타났다.

• International Journal of Reliability and Applications
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• 제16권1호
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• pp.35-53
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• 2015

This investigation deals with reliability and sensitivity analysis of a repairable embedded system with standby wherein repairman takes multiple vacations. The hardware system consists of 'M' operating and 'S' standby components. The repairman can leave for multiple vacations of random length during its idle time. Whenever any operating unit fails, it is immediately replaced by a standby unit if available. Moreover, governing equations of an embedded system are constructed using appropriate birth-death rates. The vacation and repair time of repairman are exponentially distributed. The matrix method is used to find the steady-state probabilities of the number of failed components in the embedded system as well as other performance measures. Reliability indexes are presented. Further, numerical experiments are carried out for various system characteristics to examine the effects of different parameter. Using a special class of neuro-fuzzy systems i.e. Adaptive Network-based Fuzzy Interference Systems (ANFIS), we also approximate various performance measures. Finally, the conclusions and future research directions are provided.

• 무역상무연구
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• 제13권
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• pp.657-677
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• 2000

Since January 1, 1999, traders, bankers and their counsels worldwide have available for their use the first set of rules exclusively dealing with standby letters of credit:the International Standby Practices(ISP98). Numerous standbys have alreadby been issued in the United States and worldwide subject to the new ISP. The international banking community is anticipating an increasing demand from their customers to issue ISP-governed undertakings. Before the adoption of ISP, traders and bankers had only the choice of issuing their standby subject to the International Chamber of Commerce's(ICC) Uniform Customs and Practices for Documentary Credits(UCP) and, to a much lesser extent, to the ICC's Uniform Rules for Demand Guarantees(URDG). However, practice showed that UCP rules are not easily adapted to regulate transnational standbys. Indeed, UCP was conceived to govern documentary credits, which are intended to serve as a means of payment. By contrast, standbys are means of guaranty. The core of UCP cannot therefore be appropriate for standby practices and, as a consequence, a number of UCP's provisions have to be excluded in the standby's text. UCP's shortcomings indicated above fulfil the requirements of a key factor for the success of uniform rules. Indeed, to achieve success in the sense of meeting the market's acceptance, any such rules should fill a widely recognized need expressed by merchant community to which such rules are addressed. The ISP cleary has such a vocation. Nonetheless, the already largely encumbered regulatory environment of guarantee devices can hardly go unnoticed. The question therefore arises as to the proper place of ISP in such a context.

• 대한산업공학회지
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• 제21권4호
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• pp.555-570
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• 1995

We consider a preventive replacement policy for a cold-standby system with N components, in which only one component is in operation at a time. If the component in operation fails, a standby component is immediately switched into operation. If all components fail, the system fails. The system is inspected at random poins in time to determine whether it is to be replaced or not. If the number of failed components at the time of inspection exceeds a threshold value r, the system is replaced. Otherwise the decision is put off until the next inspection point arrives. Under the cost structure which includes a replacement cost, a system down-time cost and a holding cost of the components, we develop an efficient procedure to find the optimal control values N and r, which minimize the expected cost per unit time.

• 한국태양에너지학회 논문집
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• 제32권4호
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• pp.90-95
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• 2012

Of school buildings, university building requires various case analysis unlike buildings in the elementary, middle and high schools in accordance with its characteristic for variables such as characteristic of department, construction structure and material, the number of persons admitted and schedule. Through the case research on the 'D' university located in Daejeon, this study made a comparison on the monthly and yearly consumption of gas and electricity of the most recent 3 years and implemented analysis on the usage pattern and standby power of air conditioning and heating by the hour and month using PCCS(Power Consumption Consulting System) as respects electricity that is considered to have a possibility of energy-saving. The result of analysis showed that enormous amount of electric power was used during the night time for freeze protection and burst in winter season and standby power was increased in winter season as a result.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.282-287
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• 2011

Of school buildings, university building requires various case analysis unlike buildings in the elementary, middle and high schools in accordance with its characteristic for variables such as characteristic of department, construction structure and material, the number of persons admitted and schedule. Through the case research on the 'D' university located in Daejeon, this study made a comparison on the monthly and yearly consumption of gas and electricity of the most recent 3 years and implemented analysis on the usage pattern and standby power of air conditioning and heating by the hour and month using PCCS(Power Consumption Consulting System) as respects electricity that is considered to have a possibility of energy-saving. The result of analysis showed that enormous amount of electric power was used during the night time for freeze protection and burst in winter season and standby power was increased in winter season as a result.

• 감성과학
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• 제11권4호
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• pp.629-636
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• 2008

현재 진행되고 있는 대부분의 로봇 연구는 특정한 목적을 수행함에 있어서 기능적으로 안정적이고 원활한 움직임을 보이는 것과 더불어 사용자가 원하는 정보를 적절하게 전달하는 것에 초점을 맞춰 진행하고 있다. 본 논문에서는 로봇의 작업수행 상태가 아닌 외부로부터 입력 값이 없는 대기상태의 행동패턴을 제시하여 보다 자연스러운 인간-로봇 상호작용을 제시하고자 하였다. 로봇의 대기상태 행동패턴을 디자인함에 있어서 비디오 판독 방법을 선택하였고, 실제 서비스업에 종사하는 10명의 사람들을 비디오로 녹화하여 사람들과 상호작용이 없는 대기상태의 반복적인 행동패턴을 관찰하였다. 각각의 비디오 데이터로부터 총 21개의 반복적 행동을 기록하였고, 비슷한 항목들을 통합하여 최종적으로 11개의 행동패턴을 추출하였다. 추출된 패턴들 가운데 6개의 대표적인 행동들을 EEEX라는 로봇에 적합하도록 인코딩 작업을 하였고, 이것들이 사람들에게 올바르게 인식되는지를 확인하기 위하여 검증실험을 수행하였다. 사람들은 대부분의 로봇 행동패턴을 실험에서 의도한 바와 같이 인식하였으나 로봇의 하드웨어 특성상 몸과 팔의 움직임에서 약간의 혼동 요소가 있었다. 추후 실험을 통해 EEEX를 대형 마트의 입구에 실제로 배치하여 대기 중에 중립행동을 보일 때와 보이지 않을 때의 손님의 관심도 차이를 조사해보고자 한다.

• 한국BIM학회 논문집
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• 제7권3호
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• pp.31-39
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• 2017

BIM is effective to improve the labor productivity of construction participants. From this point of view, it is important to analyze the outcome related with BIM Labor which covers most of the BIM investment costs. This research focuses on BIM RFI which is one of the major task of the BIM labor and analyze the outcomes. In addition, this research was quantitatively analyzed by the standby time and related cost caused by BIM labor, which affect the results of the project participants. To this end, analytical standby queue model was utilized to analyze the labor focusing on micros TASK. 11 projects were selected to analyze the results of BIM labor and RFI that the project participants requested to the BIM labor was collected. Through this, it collected variables for analyzing results, and Finally, we pulled out 4 projects for analysis. In this study, the basic results analysis of RFI processing of the BIM labor, the probabilistic analysis of BIM labor service status, and the economic analysis of BIM labor optimal inputs were performed by using the research model presented. The results of this study can be utilized to formulate the optimal strategy for BIM labor inputs(e.g. number of employees, level, time point, etc.) of the construction phase. Moreover, it can contribute to ensuring the credibility of the BIM ROI results by presenting the cost of BIM services in BIM ROI analysis and the standby cost of project participants.