• Nuclear Engineering and Technology
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• 제46권4호
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• pp.489-500
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• 2014

In this study, remote handling strategies for a large-scale argon cell facility were considered. The suggested strategies were evaluated by several types of field test. The teleoperation tasks were performed using a developed remote handling system, which enabled traveling over entire cell area using a bridge transport system. Each arm of the system had six DOFs (degrees of freedom), and the bridge transport system had four DOFs. However, despite the dexterous manipulators and redundant monitoring system, many operators, including professionals, experienced difficulties in operating the remote handling system. This was because of the lack of a strategy for handling the installed camera system, and the difficulty in recognizing the gripper pose, which might fall outside the FOV (field of vision) of the system during teleoperation. Hence, in this paper, several considerations for the remote handling tasks performed in the target facility were discussed, and the tasks were analyzed based on ergonomic factors such as the workload. Toward the development of a successful operation strategy, several ergonomic issues, such as active/passive view of the remote handling system, eye/hand alignment, and FOV were considered. Furthermore, using the method for classifying remote handling tasks, several unit tasks were defined and evaluated.

• Journal of Communications and Networks
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• 제14권3호
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• pp.257-266
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• 2012

A decode-and-forward two-way relay system benefits from orthogonal frequency division multiplexing (OFDM) and relay transmission. In this paper, we consider a decode-and-forward two-way relay system over OFDMwith two strategies: A joint subcarrier matching algorithm and a power allocation algorithm operating with a total power constraint for all subcarriers. The two strategies are studied based on average capacity using numerical analysis by uniformly allocating power constraints for each subcarrier matching group. An optimal subcarrier matching algorithm is proposed to match subcarriers in order of channel power gain for both transmission sides. Power allocation is defined based on equally distributing the capacity of each hop in each matching group. Afterward, a modified water-filling algorithm is also considered to allocate the power among all matching groups in order to increase the overall capacity of the network. Finally, Monte Carlo simulations are completed to confirm the numerical results and show the advantages of the joint subcarrier matching, power allocation and water filling algorithms, respectively.

• 한국산학기술학회논문지
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• 제16권7호
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• pp.4349-4356
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• 2015

본 연구는 현재 우리나라 컨테이너터미널에 적용가능한 친환경 운영기술 요인들을 도출하고, 관련 실무자들을 대상으로 한 실증분석을 통하여 친환경 컨테이너터미널 운영기술들에 대한 항목별 중요도와 만족도의 차이를 Importance-Performance Analysis로 검증함으로써 친환경 컨테이너터미널 운영기술에 대한 향후 방안을 제시하고자 하였다. 본 연구의 결과로 친환경 컨테이너터미널 운영기술 평가항목들 중 '빈이동 최소화'가 가장 중요한 요소로, '전기식 TC'가 가장 만족한 항목으로 분석되었다. 20개의 친환경 컨테이너터미널 운영기술 항목들은 '터미널 안벽시스템', '터미널 야드시스템', '터미널 접안지원 시스템'의 3개 요인으로 도출되었다. 이러한 결과들은 향후 우리나라 친환경 컨테이너터미널에 관련한 운영 정책수립 및 관리지침에 기여할 것으로 기대된다.

• 상하수도학회지
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• 제24권2호
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• pp.157-164
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• 2010

Seawater desalination has vest interest in terms of ultimate water resources for the countries suffering lack of water supply. Water demand is steadily increasing due to the population growth and industrialization in Asia. The objectives of this study are to prospect the desalination market in Asia countries including China, India and Singapore, and to propose possible strategies of getting through Asia water market. Water supply in China is increasing up to $5,322,060m^3$/d in 2015. Northeast coastal areas such as Tianjin, Shandong, Hubei, and Liaoning are expected rapid increase for water demand. The investment of water supply in India would be 1.74 billion dollars during 2006 to 2015. Chennai, Kutch, and Pondicherry have possibility in introducing seawater desalination plants. Singapore is focusing on water reuse, and operating three NEWater plants (water reuse plants). BOT with total solution providing financing, construction, operation etc. is an adequate strategy to getting through China water market, while desalination plant project connecting with power plant is desirable in India. The cooperative system with Korea and Singapore creates synergy effect regarding planning and operating experience of Singapore and EPC ability of Korea.

• 한국수소및신에너지학회논문집
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• 제20권2호
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• pp.104-115
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• 2009

In case of residential fuel cell system, it is significant to stably supply heat and power to a house with high efficiency and low cost for the successful commercialization. In this paper, the control strategy analysis has been performed to minimize the total cost including capital and operating cost of the residential fuel cell system. The proposed analysis methodology is based on the simulator including the efficiency models as well as the cost data for fuel cell components. The load control strategy is the key factor to decide the system efficiency and thus the cost analysis is performed when the fuel cell system is operated for several different load control logics. Additionally, annual efficiency of the system based on the seasonal load data is calculated since system efficiency is changeable according to the electric and heat demand change. As a result, the hybrid load control combined electricity oriented control and heat oriented control has the most economical operation.

• 에너지공학
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• 제11권1호
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• pp.59-66
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• 2002

수직 통합된 체제의 전력회사가 6개의 발전회사와 1개의 판매회사로 분리되고 전력거래소를 통한 전력거래가 본격화되면서 발전회사는 자체 소유 발전설비의 공급가능용량을 어떻게 활용하느냐에 따라 영업상 수익의 영향을 받게 된다. 특히, 하루 전 발표되는 한계가격(System Marginal Price, Base Load Marginal Price)에 맞도록 전력생산을 위한 발전 비용함수를 적용한다면 익일의 공급가능용량이 최적 배분됨으로써, 변동비 반영 시장(Cost based Generation Pool)과 입찰가격 반영 발전시장(Price Bidding Generation Pool)에 적용될 계통운영보조서비스의 계약 물량 산출 및 익일 생산비용의 최적화를위한 입찰전략(Bidding Strategies) 수립이 가능해 지므로 보유 설비에 대한 최적이용이 가능하게 된다. 따라서 본 논문에서는 수요예측 오차와 과거 시장운영 실적을 기초로 년 간 유지보수 계획을 수립하고, 계통운영보조서비스에 대한 계약물량 산출과 개개 발전기의 비용함수 산출, 적용을 통한 발전설비의 효율적인 입찰 방안에 대해 논하고자 한다.

• 한국항공운항학회지
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• 제25권3호
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• pp.89-100
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• 2017

In order for the international aviation community to efficiently and safely manage the gradual increase of air passenger demand, direction suggestions of airport traffic prediction based on future airport capacity requirements, airport design and infrastructure establishment is utilized by airport traffic data that is m comparable internationally. It is a global trend to pursue more efficient airport operating system structure to accept air passenger demand through more realistic comparable data in order to escape from the structure of reckless airport establishment and infrastructure composition based on passenger demand predictions referring to simple statistical data that has existed in the past. This study aimed to seek effective operational measures for the New Jeju airport scheduled to be opened in 2025 by time-series analysis. This study also analysed airport operation strategies, air traffic distribution strategies, cargo volume increase rates and its effectiveness of airports adopting the multi-airport system that have similar operational practices and geographical conditions. This study sought the most appropriate multi airport system application measures for New Jeju airport to promote efficiency and international competitiveness.

• KIEE International Transactions on Power Engineering
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• 제3A권3호
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• pp.168-176
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• 2003

The Korea Electric Power Corporation (KEPCO) has installed an 80 MY A Unified Power Flow Controller (UPFC) at its 154㎸ 'Kang-Jin Substation in South Korea. The device, manufactured by Siemens & Hyusung, has been operational since October 2002. The Korea Electric Power Research Institute (KEPRI), a division of KEPCO was tasked to study operational strategies that could be employed for the UPFC and surrounding reactive support devices concerning problems of low voltages and overloads in the Mokpo & Gwangju areas. Particular apprehension surrounded the possibility of delay in the installation of a new 345㎸ transmission line from 2005 to beyond 2010. The studies were to specifically determine whether these problems could be eliminated by application of a UPFC. The analysis included determining the UPFC operating point under various conditions, investigations of the coordination between the UPFC and a HYDC line terminating in this area, and the design of a supplementary damping controller for the UFPC. This paper summarizes the results of those studies, demonstrating the dynamic characteristics of the operation of this UPFC operation in the Korean power system.

• 한국태양에너지학회 논문집
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• 제27권1호
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• pp.47-54
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• 2007

Interests on renewable energy are increased due to oil price and environmental problems aroused from the fossil energy usage. In this study, performances of a solar assisted hybrid heat pump system are analyzed by experimental method. The developed system could runs at two types of operating mode. When the storage temperature is higher than the set temperature, the stored hot water in storage tank is supplied to the load directly. On the other hand, when the storage temperature lower than the set temperature, the water inside of the storage tank is used as heat source of the heat pump. In this study, the system control temperature for the alternation of the operating mode is set to $40^{\circ}C$ of the storage tank outlet. As results, it is founded that the COP of the developed heat pump system shows between 3.0 and 3.5. It is resonable performance for the heating system with a renewable energy as secondary heat source. The solar collect used in this study could supplies heat to the storage tank at over 400 W/m2 solar intensity. If the irradiation is lower than the 400 W/m2, the circulation pump stored and it could not supply heat to the storage tank. It is found that the difference temperature between the outlet of the storage tank and collector is $3^{\circ}C$. Even though, the extended study should be conducted to get a optimum performance of the developed system with various operating condition and control strategies.

• 한국항만학회지
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• 제13권2호
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• pp.245-254
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• 1999

This paper aims to derive the strategies for the container terminal in Pusan. So it has focused on analyzing the current conditions of Pusan container terminal while evaluating the difficulties arising from the existing facilities/equipment and the operating system in the Pusan Korea Container Terminal through the workers at the container terminal and at off-dock CY. The object of this study is to assist the existing terminals to operate the facilities/equipment reasonably and to contribute shaping the ports policy which will be the basis of constructing new ports that will remain competitive while maintaining superiority over the ports in northeast area. According to the analysis 68% of the supplier answered that their terminal services which are the most important factor in running a terminal were superior to the other while only 28% of the user answered that they thought the current services were superior. For the areas of supplementing the terminal the people working at the terminal answered in the order of business operation equipment the number of berth service and management ability while the user answered in the order of service computer system transportation system and equipment. According to the regression analysis it became clear that there should be more effort toward improving or supplementing the facility scale facility usage charge transportation facilities which will assist in developing competitiveness of the terminal. It was also noted that management ability and business ability were mentioned as the important factors in operating a terminal.