• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.181-188
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• 2016

This paper demonstrates that centralized economic load dispatch optimization is much more economical than independent optimization carried out by individual power generating companies. The algorithm applied here optimizes by balancing the generation power at the valve-point, then readjusting generation power by comparing incremental operating cost incurred by marginal increase in the generation power and decremental operating cost likewise incurred by marginal decrease in the generation power. Upon comparing 3 individual optimization cases of 10, 13, and 40 generators respectively with centralized optimization of 63 generators, centralized operation for economic load dispatch optimization has proven to maximize economic benefits by markedly reducing operation costs of individual optimization.

• Korean Management Science Review
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• v.27 no.2
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• pp.21-29
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• 2010

We consider an economic approach for spectrum operations in mobile networks. We present the investment function of base stations according to the number of FAs assuming the linearity of cell splitting. We show that there is an economic amount of spectrum which corresponds to the optimal number of FAs that minimizes the investment. We analyze the impact of the cost structure and the traffic distribution in base stations on the economic amount of spectrum. This paper is applicable to an economic spectrum operation for mobile operators. In addition, the national regulatory authority can use the economic amount of spectrum as the minimal amount for spectrum allocation.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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• pp.1724-1738
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• 2016

This paper was researched on economic feasibility and sensibility of operation to offshore cage culture for cod. Offshore cage culture for cod needs to invest high budget what to construction and operation. And it was required variety methods about analysis of economic feasibility. Therefore, these were studied NPV, B/C and sensitivity for each by assuming a six scenarios considering the product performance according to the size of cod and culturing methods of fingerlings, etc. As a results, even though economy, if efficiency is low, it is a priority need the technical development to promote the feed efficiency to increase economic feasibility and should make efforts to enhance the business economy to strengthen the price competitiveness pricing with high quality products through quality control and brand recognition of cod. It expects to be used as a reference for related research in the future by deriving policy implications based on the method of analysis of the economic feasibility on offshore cage culture for cod.

• Journal of agriculture & life science
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• v.44 no.6
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• pp.191-199
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• 2010

How to determine rental rates of agricultural machinery operation is the most important factor for economic units which are consigned to practice agricultural operations. Economic units as consigner for agricultural operations include agricultural cooperatives, local government, and farm operators, and so on. Thus the methods to set a rental rate of agricultural machinery operation are different across these economic units. This study describes benefits and problems associated with the model of cost accounting which is used as a method to determine a rental rate of agricultural machinery operation, and suggests a theoretical desirability of the rental pricing method, based on an accounting system and information on costs.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.653-661
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• 2017

This study compares and analyzes the operation costs of traditional and direct delivery strategies considering carbon emissions. For the determination of minimum operation costs and order quantity, we use the Economic Order Quantity (EOQ) model, which is the proper method for calculate the operation costs by logistics strategy. Using the classical EOQ model, we expand the EOQ model considering carbon emissions and domestic logistics environment. We conduct an empirical study on two agri-food logistics strategies under limitation of the carbon emissions using the expanded EOQ model. From the results of the empirical study, we find that the operation costs of direct delivery strategy are about 50% lower than those of the traditional strategy. Economic order quantity is also smaller than that of the traditional strategy. These results indicate that agri-food products can be transported quickly and freshly under direct delivery strategy. Consequently, considering carbon emissions, direct delivery logistics strategy are analyzed to have more positive effect on economic and environmental issues than existing logistics strategy. It is judged that direct strategy will also increase the freshness of agricultural products.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.3
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• pp.262-268
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• 2020

The IMO (International Maritime Organization) has mandated the restriction of SOx emissions to 0.5 % for all international sailing vessels since January 2020. And, a number of countries have designated emission control areas for stricter environmental regulations. Three representative methods have been suggested to cope with these regulations; using low-sulphur oil, installing a scrubber, or using LNG (Liquefied Natural Gas) as fuel. In this paper, economic analysis was performed by comparing the method of installing a scrubber with the method of using low-sulphur oil without installing additional equipment. We suggested plausible layouts and compared the pros and cons of dif erent scrubber types for retrofitting. We selected an international sailing ship as the target vessel and estimated payback time and benefits based on navigation route, fuel consumption, and installation and operation costs. Two case of oil prices were analyzed considering the uncertainty of fuel oil price fluctuation. We found that the expected payback time of investment varies from 1 year to 3.5 years depending on the operation ratio of emission control areas and the fuel oil price change.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.9 no.1
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• pp.45-58
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• 2001

According to the liberalization of the air transport industry, the operation of airport also takes account of economic efficiency. The owners or the operators of an airport or airport systems want to know what is the best way to achieve the best performance in the aspect of economic efficiency and they are willing to improve the airport operation system. Prerequisite for the improvement of economic efficiency is to measure the performance of not only their own airports but the other airports. This study presents the result of performance measurement of Korean airports. The overall costs performance, labor productivity, capital productivity, revenue performance and profit performance are estimated and interpreted. As conclusions, the suggestion about airport system improvement is presented.

• Journal of Korea Port Economic Association
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• v.22 no.2
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• pp.61-82
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• 2006

In order to cope with improvement of labor cost and cargo volume, Korean ports, especially Busan port, are in need of many new facilities. Of course, current facilities should be fully used, and at the same time it needs to make every effort to maximize its productivity as well as cost saving. To this end, this study has decided to focus on automatic yard operation suitable to the domestic container terminal environments, making a survey of many advanced container terminals, trying to find out their common factors, and finally suggesting several alternatives based on the combination of these factors. Also, this study has suggested the present value of initial investment and operating cost by alternative, and at the same time presented the relationship between cargo handling volume and cost/revenue of the optimal alternative, so that it may be of help in decision making.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1064-1072
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• 2017

The power of controlled generators in microgrids randomly fluctuate because of the stochastic volatility of the outputs of photovoltaic systems and wind turbines as well as the load demands. To address and dispatch these stochastic factors for daily operations, a dynamic economic dispatch model with the goal of minimizing the generation cost is established via chance-constrained programming. A Monte Carlo simulation combined with particle swarm optimization algorithm is employed to optimize the model. The simulation results show that both the objective function and constraint condition have been tightened and that the operation costs have increased. A higher stability of the system corresponds to the higher operation costs of controlled generators. These operation costs also increase along with the confidence levels for the objective function and constraints.

• Journal of Korea Water Resources Association
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• v.56 no.8
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• pp.485-496
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• 2023

Recently, South Korea has been making efforts to mitigate the risk of water scarcity during droughts by utilizing various drought response measures in dam operations. While various studies have been conducted on this topic, there is currently a lack of research on the economic effects of drought response measures. In this study, we evaluated the economic effects of drought response measures on nationwide multipurpose dams by using a long-term simulated inflow model based on ARIMA and Copula and a dam operation model that reflects drought response measures. The results showed that the expected benefits per unit flow rate were highest for coordinated operation and alternative water supply measures, at KRW 1,176 and KRW 1,139, respectively, while the benefits of emergency water supply utilization and water supply adjustment were estimated at KRW 956 and KRW 875, respectively. Additionally, when we examined the changes in the economic benefits of drought response measures based on the assumption of increased drought severity in the future, the changes in the drought risk resulting from reduced inflow increased the economic benefits of all drought response measures. The economic benefits of water supply adjustment increased by 2.6% compared to the baseline, while the economic benefits of coordinated operation and alternative water supply measures increased by 11.7% compared to the baseline. This suggests that dam-network-based measures, such as coordinated operation and alternative water supply measures, are crucial as drought risk increases. This study is expected to serve as a fundamental reference for selecting and utilizing drought response measures in the future.