• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.5
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• pp.1-7
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• 2001

Factors which affect largely the economics of lighting system, are initial installation costs, maintenance costs, energy costs as so on. In these costs, maintenance cost, lamp replacement labor cost, luminaire cleaning cost et al. so the economics of lighting system are evaluated different by maintenance planning. It is important to evaluate which lighting system would be economically advantageous in a initial design. In this study, the importance of maintenance factor is verified by the evaluations of the economics of lighting systems while maintenance factor is varied composition factors in ZCM which is used to calculate the average illuminance.

• Journal of Advanced Research in Ocean Engineering
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• v.3 no.4
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• pp.184-192
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• 2017

The Korea Offshore Wind Power (KWOP) cooperation is planning to construct offshore wind energy farms with an overall rated power of 2.5 GW along the southwestern coast by 2019. Hitherto, various structural types of support structures for offshore wind turbines have been being proposed, but these structures have lacked economic analysis studies. Therefore, their economical superiority to existing types has been difficult to guarantee. An offshore structure with economic efficiency will have a minimum amount of mobilizing equipment and short offshore construction period because of the application of rapid installation methods. Thus, the development of a new support structure with economic efficiency is generally considered to be necessary. Accordingly, this paper proposes a newly developed and more economical jacket type for the offshore support structure. This study confirmed its structural safety and performance by conducting a structural analysis and eigenvalue analysis. The manufacturing and installation costs were then estimated. As a result, the new jacket type of offshore support structure proposed in this study significantly reduced the manufacturing and installation costs. Therefore, it is expected that the proposed jacket will contribute to reducing construction expenses for new wind power farms and invigorating wind power farm businesses.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.4
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• pp.451-456
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• 2013

Development of the technologies for offshore wind power is proceeding actively and the installation capacity is continuously increasing because of its many advantages in comparison with the land wind power. Accordingly, project for Southwestern 2.5GW offshore wind power plant is in progress in Korea. Design of electric power systems for offshore wind power plant is very important due to its high investment and operational costs. Hence, it needs to be designed in order to minimize costs. This way can be employed in determining the installation location of offshore substation for HVAC wind power plant. According to the offshore substation site, MV inter-array cable and HV export cable lengths vary and they change a total cost regarding submarine cable. This paper represents cost models with variables which are MV inter-array cable and HV export cable lengths to locate the offshore substation for HVAC wind power plant. It is classified into submarine cable installation cost, reactive power compensator installation cost, ohmic losses, and unsupplied energy cost. By minimizing a total cost, an appropriate installation site of the offshore substation is determined.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.165-170
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• 2004

This paper presents summary results of direct interview survey of Korean industrial customers conducted to evaluate the direct and short duration interruption costs resulting from local random electrical supply interruptions. The cost is evaluated using the questionnaires authors designed, which are mainly on the experience or preparatory actions consumers predicted they would take. Economic evaluation of reliability that traditionally takes into account duration and frequency of interruption does not accurately reflect the lost value or economic impacts of industrial customer, especially large size, caused by any kind of interruption. So, to imply the substantial difference in costs incurred by different customer group, the authors apply the international standards, i.e. IEC, IEEE, to the analysis on the interruption costs.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.3
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• pp.54-60
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• 2015

There are 5 purification plants with the adopted advanced water purification treatment process in Korea. Annual operating costs were 8,990 million won including purchase cost of oxygen and power usage charges. We need research to optimize, in the future, when considering the direction of domestic water treatment continues to adopt advanced water treatment process. In this paper, calculate the optimal operating costs by injected the oxygen gas, used power cost. approximately 25% of the operating costs can be reduced when injected the ozone gas is 1.0ppm than 2.0ppm, the necessary amount of oxygen is increased then power is lower. so operating costs are decided according to oxygen costs. On the other hand, high ozone concentration 2.0ppm, the necessary power is increased then amount of oxygen is lower. Therefore, in the case of G purification plant, the controlling factor of the input ozone concentration 2ppm, PID control operation by setting the concentration of over 10Wt% is efficient. The installed capacity is the more little the more better when considering on Ozone injection rate in the process of water treatment.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.3
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• pp.93-107
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• 1999

We consider the development of an integer programming model and algorithm for the ATM switching node location problem. There are two kinds of facilities, hub facilities and remote facilities, with different capacities and installation costs. Each customer needs to be connected to one or more hub facilities via remote facilities, where the hub(remote) facilities need to be installed at the same candidate installation site of hub(remote) facility. We are given a set of customers with each demand requirements, a set of candidate installation sites of facilities, and connection costs between facilities, We need to determine the locations to place facilities, the number of facilities for each selected location, the set of customers who are connected to each installed hub facilities via installed remote facilities with minimum costs, while satisfying demand requirements of each customer. We formulate this problem as a general integer programming problem and solve it to optimality. In this paper, we develop a branch-and-cut algorithm with path variables. In the algorithm, we consider the integer knapsack polytope and derive valid inequalities. Computational experiments show that the algorithm works well in the real world situation. The results of this research can be used to develop optimization algorithms to solve capacitated facility location problems.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.4
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• pp.88-96
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• 2011

This paper assesses interruption costs on the industry load through using the microscopic method. For assessment, the questionnaire was made on Korea Standard Industry Categorization which is composed of 28 type of industry Then, the survey was distributed to 1889 business in 12 area by staffs of KEPCO. The collected data is changed to the trustworthy data by using Bad Data Selection method and then the interruption costs of industry load was calculated by Tobit Regression which is tool analysing both collected data and the others.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.7
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• pp.75-80
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• 2014

The small wind turbines has the merits of setting up with low costs by individuals, and get the energy saving effects that, it has the secured, separate markets from the big range systems, and the developing of it is continuously proceeding. The objective of this paper is to provide the design characteristics analysis of a permanent magnet synchronous generator(PMSG) skewed for magnet of rotor, the main advantage to be explored with the use of a split core design is the reduction in manufacturing costs and its simplicity in manufacture, compared to the manufacturing costs of a core skew PM machine. This thesis is aiming mainly analyzing the characteristics of the prototype to verify through Finite Element Method(FEM) and tests.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.4
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• pp.131-137
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• 2004

The impacts of electric service interruption to customers depend on customer and interruption characteristics. Customer characteristics include demographic aspects (residential type, and number of household members) and power supply types whereas interruption characteristics include frequency, duration, time, and day of interruption. Accordingly evaluation of these customer interruption costs is very complicated and subjective. For residential customers, customer survey method seems most appropriate because interruption impact to residential customers is intangible. In other. words, the value of housework or lost leisure due to interruption is individual. Accordingly, this paper selected the customer survey method to assess the interruption costs for residential customers.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.5
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• pp.207-217
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• 2018

Recently, the importance of energy demand management, particularly peak load control, has been increasing due to the policy changes of the Second Energy Basic Plan. Even though the installation of distributed generation systems such as Photovoltaic and energy storage systems (ESS) are encouraged, high initial installation costs make it difficult to expand their supply. In this study, the power consumption of a university building was measured in real time and the measured power consumption data was used to calculate the optimal installation capacity of the Photovoltaic and ESS, respectively. In order to calculate the optimal capacity, it is necessary to analyze the operation methods of the Photovoltaic and ESS while considering the KEPCO electricity billing system, power consumption patterns of the building, installation costs of the Photovoltaic and ESS, estimated savings on electric charges, and life time. In this study, the power consumption of the university building with a daily power consumption of approximately 200kWh and a peak power of approximately 20kW was measured per minute. An economic analysis conducted using these measured data showed that the optimal capacity was approximately 30kW for Photovoltaic and approximately 7kWh for ESS.