• Current Photovoltaic Research
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• v.11 no.4
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• pp.134-143
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• 2023

Efforts are being made to respond to global warming. Interest in and demand for the private sector-led RE100 campaign is also increasing. Self-built solar power generation, one of the implementation tools for RE100, is not expanding. However, it can be an economical means of implementation in the long run. In this study, we intend to analyze the impact on the optimal ratio of self-solar power generation using HOMER simulation. OPR defines the optimal solar power generation ratio and looks into what changes there are in the optimal solar power ratio when self-power consumption increases and external power purchase price changes. As a result, the optimal rate of self-solar power generation has a low impact even if self-power consumption increases. As the external power unit price increases, the optimal ratio increases, and at a power unit price of 100 KRW/kWh, OPR is 24%; at 200 KRW/kWh OPR is 31%; and at 300 KRW/kWh OPR is 34%. This shows that the electricity price replaced during the life cycle has a high impact on the economic feasibility of solar power generation. However, when the external power unit price reached a certain level, the increase in OPR decreased. This shows that it is difficult for domestic companies to achieve RE100 based on the economic feasibility of solar energy alone. Therefore, efforts are needed to supply renewable energy in the public sector.

• Journal of the Korean Society for Railway
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• v.11 no.1
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• pp.107-113
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• 2008

As it recently appears that LCC (Life Cycle Cost) analysis may be considered as an essential method for economic evaluation of infrastructures. Many researches have been made to assess LCC of each facility based on reasonable methods. However, expected maintenance repair cost must be reasonably estimated to enhance the reliability of LCC analysis through systematic and rational methods. This study is intended to propose a rational approach to reliability-based LCC analysis of high-speed railway steel bridges considering lifetime corrosion and fatigue damage. However in Korea, since high speed railway steel bridges are only recently constructed, no direct statistical data are available for the account of the maintenance cost and thus their maintenance characteristics are not clear yet. In this paper, for the assessment of expected maintenance/repair cost, the fatigue system reliability analysis incorporating the corrosion effect is proposed by considering the corrosion and fatigue damage using measured data of high speed railway steel bridges. A model proposed by Rahgozar, of at for fatigue notch factor considering the corrosion effect is used in order to incorporate the corrosion effect into the fatigue strength reduction and S-N curve. Finally, the effectiveness of LCC model proposed for high-speed railway steel bridges is demonstrated by a numerical example.

• Journal of IKEEE
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• v.14 no.3
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• pp.236-243
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• 2010

Power quality mitigation devices play an important role in lots of industrial segments. Although there were many devices available in the market, the selection of an appropriate device specially for voltage sags and interruptions mitigation has been a challenge in the utility and customer for several years. It usually depends on technical and economic characteristics of the device. Nevertheless, most mitigation method is selected by rule of thumb or empirical method. In this paper, the life cycle cost analysis for the probabilistic risk assesment of voltage sag mitigation method is performed using either the deterministic or probabilistic approach. The difference between a deterministic and a probabilistic cost analysis approach is illustrated with five different case studies. This paper not only provides a comparison of life cycle costing of various devices but it also indirectly shows the possible savings due to the mitigation of voltage sags in the form of a project balance chart.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.8
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• pp.439-447
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• 2009

Cogeneration system produces power as well as heat recovered from waste heat during power generation process. This system has higher energy efficiency than that of the power plant. In this study the optimal design for the cogeneration system with the increase of the capacity considering life cycle cost(LCC) analysis has been performed in the general facilities such as hotels and hospitals under the assumption of electricity cost of 95 won/kWh, the initial cost of cogeneration system of 1,500,000 won!kW and the value of 0.5${\sim}$1.0 in the ratio of heat to power. The optimal ratio of cogeneration capacity divided by average electricity load of facility was found out more than 0.5 in case of electricity cost with the increase of>30%, and the percentage of $CO_2$ reduction was about 9%. The most important factors in the economic analysis of cogeneration system was found out the electrity cost and the initial cost of cogeneration system. Also the ratio of heat to power at the value of>0.5 was not affected in the economy of cogeneration system, but was very important in the $CO_2$ reduction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.156-159
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• 2013

The ICT technology by using smartphone is leading the world. Apple opened the smart age with its smartphone on the first place in the world. In 2013, Samsung of Korea is spotlighted in the world, but China will run after Samsung with medium- and low-priced smartphones equipped with functionality and low and medium prices after 2014. That is, the life cycle of ICT technology gets shorter, and the volume of investment is increased. There is increasing uncertainty of enterprises and nations because the expanded volume of investment. Therefore, it is very important to predict emerging ICT technology, and investment development. Korea based on the creative economy is at the point of strengthening ICT. Therefore, this study aims to analyze intellectual property rights (patent) and the ICT market environment for the emerging ICT technology. The result of analysis will contribute to studying the intellectual property rights (patent) and the R&D matrix module in the ICT market environment for discovering and predicting national emerging ICT technology.

• Korean Journal of Construction Engineering and Management
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• v.15 no.3
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• pp.92-102
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• 2014

Recently, various methods such as energy reduction, Greenhouse gas and etc., has been suggested worldwide. Korea has a lot of deteriorated houses, thus there are many demands for the remodeling. However such studies are scarce. This study analyzed the types of deteriorated housing, also suggests technology list to remodeling through domestic, foreign practices and existing research. This study suggested combination of technology list for small house remodeling by energy simulation and Life Cycle Cost related to windows, insulation and doors. This study that can be applied to the technical performance and economy of the basic research would be the basis of the analysis technique.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.431-435
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• 2007

Green Building Certification Program, which was first introduced to residential buildings in Korea in 2002, has been put on track. This program is expected to bring about the effect in the economic viewpoint that was based on a life-cycle-cost analysis, not to mention the environmental viewpoint. However, given the fact that the existing model for feasibility analysis focusing on early investment cost can hardly be applicable to the green buildings because of lacking the life-cycle-cost reduction factor, it remains still difficult to conduct an objective evaluation. The study thus was intended to identify the factors that should be additionally considered in conducting the feasibility study to be implemented through the analysis of the certification items of green buildings as a preliminary study in structuring the evaluation model for feasibility analysis of green buildings.

• Resources Recycling
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• v.22 no.4
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• pp.55-61
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• 2013

In this study, eco efficiency analysis is performed to analyze Neodymium (Nd) containing permanent magnet recycling process. Life cycle assessment (LCA) and life cycle costing (LCC) are used to apply eco efficiency analysis. In the environmental aspects, global warming potential (GWP) of 1kg permanent magnet is 1.25E + 00 kg $CO_2$ eq. and abiotic resource depletion potential (ADP) is 1.10E - 02 Sb eq. This recycling process costs about 2130 KWR. Environmental efficiency of GWP is at 6.43 and ADP is at 5.32 when compared with vigin metal. Economic efficiency is at 6.74. This study confirms that Nd containing permanent magnet recycling process is sustainable system because of environmental and economical improvement.

• Journal of Climate Change Research
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• v.9 no.1
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• pp.75-80
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• 2018

The problem of water shortages and water related disasters caused by climate change has increased the seriousness of water problems and the importance of water treatment technology capable of securing clean water is expanding. In this study, we analyzed not only the water pollutant generated by the filtration system technology of various water treatment technologies but also the indirect greenhouse gas emissions generation, and analyzed the influence on the environment. The subjects of study are Fabric Filter, Reverse Osmosis System and Pressurized Microfiltration Device which are widely used for water treatment and we analyzed the impact on the environment using the Life Cycle Assessment (LCA) method using the electricity amount necessary for use, the water purification efficiency, the throughput per ton and the cost. The amount of greenhouse gas generated when the Pressurized Microfiltration Device operates for 1 year is $2.15E+04kg\;CO_2-eq$., Fabric Filter is $3.29E+04kg\;CO_2-eq$., and Reverse Osmosis System is $1.68E+05kg\;CO_2-eq$. As a result of analyzing the amount of greenhouse gas generated at the time of purifying 1 ton of the Pressurized Microfiltration Device and the conventional filtration system, the Pressurized Microfiltration Device was $20.5g\;CO_2-eq$., Fabric Filter was $34.7g\;CO_2-eq$., and Reverse Osmosis System was $191.7g\;CO_2-eq$. The amount of greenhouse gas generated was calculated to be 41.0% less than that of the Fabric Filter by the Pressurized Microfiltration Device and 89.3% less than the Reverse Osmosis System. From the viewpoint of climate change, it is necessary to select a filtration system that takes climate change into account, not from the viewpoint of water quality removal efficiency and economic efficiency according to future water treatment applications, and it is necessary to select a water treatment filtration system more researches and improvements will be made for.

• Convergence Security Journal
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• v.23 no.1
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• pp.109-115
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• 2023

The future outlook for defense faces various and challenging environments such as the acceleration of uncertainty in the global security landscape and limitations in domestic social and economic conditions. In response, the Ministry of National Defense seeks to address the problems and threats through defense innovation based on scientific and technological advancements such as artificial intelligence, drones, and robots. To introduce advanced AI-based technology, it is essential to integrate and utilize data on IT environments such as cloud and 5G. However, existing traditional security policies face difficulties in data sharing and utilization due to mainly system-oriented security policies and uniform security measures. This study proposes a paradigm shift to a data value-based security policy based on theoretical background on data valuation and life-cycle management. Through this, it is expected to facilitate the implementation of scientific and technological innovations for national defense based on data-based task activation and new technology introduction.