• KIEAE Journal
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• v.6 no.1
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• pp.3-10
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• 2006

As has been expected, economic factors are a major consideration in almost every decision in building design process. Assuming that improving a lighting system, existing or proposed, will reduce operating cost, what preliminary economic guidelines can be established to determine whether any proposed investment appears cost effective? In such a case a reasonable technique to compare system costs is by life-cycle costing. Stated simply, a life-cycle cost represents the total cost of a system over its entire life cycle, that is, the sum of first cost and all future costs. This paper aims to exemplify the benefit of daylighting in term of economic consideration. Four different electric lighting system designs are proposed and a lighting control system that is continuously operating according to the level of daylight in the space has been adapted. The accumulated performance of electric and daylighting is figured out to declare the effective depth of daylight in the space. The analysis on the saving amount of lighting energy due to daylight has been undertaken in answer to the question, that is, several projects are being considered, which is the most desirable from the cost-effectiveness viewpoint. The result shows clearly that although denser layout of lighting fixtures might be more effective to interface to the level of daylight ceaselessly changeable, its economic benefit may not meet the expected criterion the reason of increased initial investment and maintenance cost for the fixtures and control hardware.

• Design & Manufacturing
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• v.10 no.2
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• pp.1-5
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• 2016

High-speed and high-torque performance is required in the ultra-high speed electric injection molding machine field. To implement this performance, the big-size inverter is needed and the corresponding converter should be used. In this case, the whole cost for configuring the system will be increased. In this paper, we introduce a method which is able to reduce the energy and the cost for configuring the system using the energy regeneration. The energy regeneration method is based on reusing the regeneration power generated at the electric motor during decelerating the injection motion. In this paper, we demonstrate the effectiveness of the method by using the ultra-high speed injection motion.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.9
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• pp.1249-1259
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• 2012

This paper proposes a Web Based Online Outage Cost Assessment and Information System(WOOCAIS) for power system outage cost assessment. The proposed WOOCAIS is a kind of web based survey method for outage cost assessment. While conventional survey methods have done outage cost assessment based on survey paper lists collected by post mail or visiting customers, the proposed WOOCAIS is a web based online survey operation and assessment system. Therefore, it can curtail expenditure for survey and also is more convenient than conventional method. It will be set up for actual outage cost assessment system of KEPCO in South Korea in the near future. The WOOCAIS will be applied in various research and actual planning and operation areas. First of all, the assessed results may be not only applied as one of objective function for generation system and grid expansion but also operational planning problems in power system.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.05a
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• pp.249-250
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• 2018

• Journal of Hydrogen and New Energy
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• v.33 no.3
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• pp.247-254
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• 2022

Slush hydrogen containing liquid and solid hydrogen is expected to achieve zero boil-off by suppressing boil-off gas because heat of fusion for solid absorbe the heat ingress from atmosphere. In this paper, quantitative analysis on storage cost considering specific energy consumption between 1,000 m³ class liquid hydrogen storage system with re-liquefaction and slush hydrogen storage system during equivalent zero boil off period. Even though approximately 50% of total storage capacity should be converted into solid phase during the initial cargo bunkering, total energy consumption to convert into slush hydrogen is relatively 25% less than re-liquefaction energy for boil off hydrogen during zero boil off period. That's because energy consumption of slush phase change take up only 1.8% of liquefaction energy. moreover, annual revenue requirement including CAPEX, OPEX and electric cost for slush hydrogen storage could be more reduced approximately 32.5% than those of liquid hydrogen storage and specific energy storage cost ($/kg-H₂) could also be lowered by about 41.7% compared with liquid hydrogen storage.

• KIEAE Journal
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• v.15 no.4
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• pp.77-84
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• 2015

Purpose: In 2008, As the green growth policy was presented, Green Building is made any effort to propagation. In this paper, the respective technologies that are able to considerably reduce the energy demands for heating, cooling, hot-water, lighting and ventilation among the variety of technologies were selected. Method: Design factors such as (1) External insulation, (2) Triple glazing window, (3) LED lighting, (4) External venetian blind, (5) Geothermal and (6) Heat recovery ventilator were derived. In addition, energy saving effects in terms of energy demand, energy consumption and energy cost were investigated using EnergyPlus, building energy analysis tool. Result : The results were as follows. (1) It can be seen that high insulated triple glazing window, heat recovery ventilator and external insulation technology is excellent for energy demand. (2) Unlike energy demand, saving effect of energy consumption and energy cost was shown in order of Geothermal > Triple Window > Heat recovery Ventilation> Insulation> LED Lighting > EVB Blind.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2018.05a
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• pp.303-304
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• 2018

• Environmental and Resource Economics Review
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• v.30 no.1
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• pp.107-128
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• 2021

It has been recognized that implementing the marginal price mechanism to CBP is not acceptable due to the lack of revenue of the marginal generators. This study shows that it is not the problem of marginal price mechanism but the structural problems originated by the suspension of restructuring, the technical limits of RSC program and inaccuracy of the generation cost estimation method. This study explains the method to calculate the cost function in operating modes of the CC generators and proposes the modeling for the CC generators in RSC program. To implementing the cost function in operating modes could give an opportunity to change the price setting mechanism from average to marginal cost. The price setting mechanism based on the marginal cost will be one of the main points to provide the right price signals and to introduce a real-time and A/S markets to prepare the energy transition era.

• Journal of Energy Engineering
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• v.1 no.1
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• pp.87-96
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• 1992

Two major difficulties with finding an optimal solution to the heat exchanger network synthesis problems are the large solutionspace and the uncertainty in the formulation of the annual cost function. In this work, to overcome the first difficulty a problem reduction technique was developed. The second difficulty was also removed by dividing the annual cost function into four cost items. The optimal network structure for minimum equipment cost is then obtained by repeatedly applying the problem reduction technique and the heuristics in turn. The efficiency and the superiority of the method is demonstrated by examining two selected example problems.

• JOURNAL OF ELECTRICAL WORLD
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• no.6 s.54
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• pp.2-4
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• 1981