• 한국농공학회지
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• 제36권2호
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• pp.44-55
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• 1994

This paper describes the development of real-time irrigation reservoir operation models that adequately allocate available water resources for paddy rice irrigation. Water requirement deficiency index(WRDI) was proposed as a guide to evaluate the operational performance of release schemes by comparing accumulated differences between daily release requirements for irrigated areas and actual release amounts. Seven reservoir release rules were developed, which are constant release rate method (CRR), mean storage curve method(MSC), frequency analysis method of reservoir storage rate(FAS), storage requirement curve method(SRC), constant optimal storage rate method (COS), ten-day optimal storage rate method(TOS), and release optimization method(ROM). Long-term forecasting reservoir operation model(LFROM) was formulated to find an optimal release scheme which minimizes WRDIs with long-term weather generation. Rainfall sequences, rainfall amount, and evaporation amount throughout the growing season were to be forecasted and the results used as an input for the model. And short-term forecasting reservoir operation model(SFROM) was developed to find an optimal release scheme which minimizes WRDIs with short-term weather forecasts. The model uses rainfall sequences forecasted by the weather service, and uses rainfall and evaporation amounts generated according to rainfall sequences.

• 감성과학
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• 제14권1호
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• pp.7-16
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• 2011

본 연구에서는 공공자전거 운영시스템을 도입하기 위해 국내외 사례조사와 대상지역인 나주시(NaJu City)의 현지조사를 통해 운영시스템 적용 방법에 대한 사례연구를 진행하였다. 1차 조사에서는 국내외 공공자전거 시스템 적용사례를 분석하여 이용시간, 도난과 파손 위험 등의 문제점을 조사하였다. 2차 조사에서는 공공자전거 시스템 도입 예정 지역인 나주시(NaJu City)의 조사결과 시민과 관광객이 쉽게 이용할 수 있는 운영시스템의 도입이 필요한 것으로 조사되었다. 3차 조사에서는 1, 2차 조사결과를 바탕으로 프랑스 밸리브(Velib) 시스템의 문제점을 해결할 수 있는 모바일 대여/반납 프로세스와 시스템 운영절차, 통신절차의 모듈을 정리하였다. 또한, 1차 조사와 2차 조사에서 나타난 문제점인 이용방법과 민원처리 방안에 대해서도 정리하였다. 위와 같이 본 연구에서는 국내외 사례조사, 현지조사, 그리고 대여/반납 프로그램의 모듈 개발을 통해 공공자전거의 운영시스템 도입 방법을 연구하였으며 현재 나주시에서 운영시스템이 시범운행 중에 있다. 따라서 앞으로 시험운행 결과를 종합하여 좀 더 효율적인 운영시스템이 도입될 수 있도록 연구를 진행하겠다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2358-2361
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• 2003

In this paper, parallel control method that enables coordinating operations of multiple mini ice storage air conditioner is proposed based on LonWorks system. The proposed parallel control method is a kind of master/slave control method based on LonTalk network communication. In the control method, master controller leading whole system operations is determined by date to avoid the disproportion of outdoor unit operations. In addition to the above, duty shift control method is proposed to avoid redundant operations of outdoor units and to equalize the operation frequencies of them. Through some simulation tests, the proposed parallel control method and the duty shift control method are evaluated and the efficiencies of them are validated by comparing with existing methods.

• 한국지열·수열에너지학회논문집
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• 제16권4호
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• pp.24-30
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• 2020

Ground source heat pump (GSHP) systems are actively introduced as cooling and heating conditioning systems of buildings due to annual stable performance and easily maintenance. However, ground temperature imbalance is occurred when the GSHP is used for a long period. Therefore, in this study, we proposed the operation method of the system that considered the recovery time of heat source temperature. The entering water temperature (EWT) and heat exchange rate (HER) were comparatively analyzed according to the continuous and intermittent operation. Furthermore, the underground thermal environment was evaluated by numerical analysis model. As the result, the intermittent operation was a maximum of 12.3% higher HER during the heating period than the continuous operation. In addition, the overall ground heat source temperature at the intermittent operation was higher than it at the continuous operation.

• Architectural research
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• 제7권1호
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• pp.11-18
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• 2005

In today's building industry the emphasis has been geared more towards construction, thus building maintenance and life cycle have been neglected until now. A direct result of this neglect is the rapid aging of building, which leads to more cost-effective decision making methods for the prolongation of building life span. The following study is conducted in the area of Daegu and Seoul in order to develop the estimation analysis method of the annual operation cost of the Korean high-rise condominiums for the cost-effective decision making support through mathematical and statistical analyses including the present value and standardized measurement corrections. Based on the assumption that the life expectancy of the high rise condominium is 50 years, initial cost is ￦421,212/$m^2$, and a total sum of yearly operation cost during life expectancy is ￦2,154,499//$m^2$), yearly accumulated operation cost is shown as below: $AOC=0.7097t^4-38.803t^3+806.95t^2+11045t-496.52$ ($R^2=0.98$) (Here, AOC = Accumulated Operation Cost, t = given years)

• 통상정보연구
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• 제10권4호
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• pp.203-219
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• 2008

This study shows the following results. First, the assessment items of the whole exhibition operation, workforce, counselor's ability, facility and environment were important analysis factors for exhibition recognition, quality of human operation and quality of exhibition facility and environment. Second, exhibition recognition was found to be the most significant factor that influenced exhibitor's cognitive achievement, exhibition employee operation and exhibition facility. Third, exhibitors' satisfaction simultaneously increased as exhibition recognition and employee operation quality were raised. However, exhibition facility didn't strongly influence exhibitors' satisfaction. Fourth, high exhibition recognition, employee operation and exhibition facility resulted in high cognitive achievement and exhibitor's loyalty. Fifth, exhibition recognition is a highly influential factor to mediate exhibitor's cognitive achievement and exhibitors' loyalty. It implied that exhibitors' cognitive achievement and satisfaction were significantly related to the exhibition quality factor. Moreover, it indicated the effective and efficient operational method to strengthen promotional strategy, enhance the quality of employee operation, exhibition facility and environment. Thus, the results suggest a new method to evaluate exhibitor's satisfaction in the exhibition industry.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 춘계 학술논문 발표대회
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• pp.341-343
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• 2012

This study introduces a method for computation of process and operation gap in the specific construction operation(i.e., RC frame construction applying a block-grouping scheme) using CYCLONE-based simulation modeling and analysis technique. Since uncertainty of construction environment exists, a thoughtful production planning is required to effectively deal with a risk resulting in schedule delay in advance. This study presents the concepts of a time delay occurred in a process level and operation level in a operation model, and a method of measuring gap-times in each level while the simulation progresses. It helps a site manager to decide how many segmentation in a construction block is suitable for eliminating unproductive time-delays under the constrained resources (e.g., laborer, equipment). A case study presents a network model representing a three segmented RC frame work, and result obtained from the simulation experiment.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.145-150
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• 2003

The national subway went under construction in 1971, and after three years of endeavor, Seoul subway line number one opened for traffic in 1974. Line number two went under construction in 1978 and it opened for traffic in 1984. With the use of safety operation for more than 20 years, the life cycle nearly came to an end. Therefore the improvements for the safety operation are unavoidable. The total system should not be affected when the new and conventional systems are overlapped, the system operation is in the initial stage, and it confronts the situation of abnormal operation. However, there is a total lack of experience in construction and improvement for the trains that are in the use of large transport and density headway. In this paper, we propose an improvement method of the subway signalling system using ATO (Automatic Train Operation control scheme) to which the latest Digital ATC is applied, and examine the first application model of ATO system.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2012년도 추계 학술논문 발표대회
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• pp.115-117
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• 2012

Task based modeling is essential in a construction operation simulation modeling. It allows dealing with local variables or delay factors that affect productivity and improves the reusability of existing operation models. An operation model can secure reality only if it reflects the real construction processes by effectively dealing with zoning issue. However, system users have some difficulties in modeling a construction operation that is consisted of several processes having different production units. Zoning is a major modeling issue when the task based modeling method is implemented using the existing discrete event simulation systems. This paper highlights the difficulty and presents a new method that complements the zoning issues attributed to different production units. The method is described in detail by presenting the flow of entities. It is confirmed that the zoning method effectively deals with the unbalance of production units between processes and facilitates to model an operation model having processes with different production units. The "Zoning module" contributes to increasing accuracy of simulation result.

• 전력전자학회논문지
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• 제21권6호
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• pp.497-505
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• 2016

Operating wind turbine generators at maximum power point requires maximum power point tracking (MPPT) control methods. However, conventional methods cannot track the appropriate maximum power point in situations involving wind turbine systems based on a series operation strategy. These systems comprise one or more local maximum power points, and conventional methods can detect only one local maximum power point closed by a current operation point. This study proposes an advanced MPPT method for the series operation strategy of a small, grid-connected wind turbine system. In determining the appropriate maximum point, operations at certain local maximum power points are analyzed. The results show one appropriate point, which is tracked by the proposed MPPT method. The effectiveness of the proposed method is verified by the experimental results.