• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.153-160
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• 2009

The demand for super tall building construction is increasing worldwide. There has been a constant request for achieving early payback on investment by shortening the construction time. This pertains especially for the case of huge investment projects such as super tall building construction. It is very important to shorten the construction time for the building framework, which requires substantial construction time and cost, and this is directly related to the establishment of an optimum lift plan for construction. When there is a problem in the selection of the lift equipment, it is almost impossible to revise the selection, resulting in a possible failure of the project. Thus, the purpose of this study is to analyze the function and logic for the development of the process for the selection of lift equipment for super tall building projects and further development of making the analyzed process into a system. In line with this research objective, the process of selecting the optimum lift equipment by domestic construction company was investigated and analyzed as well as collecting the actual field data. The actual data were obtained by sensors installed on tower cranes at three construction sites with the help from the construction company.

• Environmental Engineering Research
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• 제12권5호
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• pp.197-200
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• 2007

Advanced control is getting increasingly demanded in water and wastewater treatment systems. Various case studies have shown significant savings in operating costs, including energy costs, and remarkably short payback times. It has been demonstrated that instrumentation, control and automation (ICA) may increase the capacity of biological nutrient removing wastewater treatment plants by 10-30% today. With further understanding and exploitation of the mechanisms involved in biological nutrient removal the improvements due to ICA may reach another 20-50% of the total system investments within the next 10-20 years. Disturbances are the reason for control of any system. In a wastewater treatment system they are mostly related to the load variations, but many disturbances are created also within the plant. In water supply systems some of the major disturbances are related the customer demand as well as to leakages or bursts in the pipelines or the distribution networks. Hardly any system operates in steady state but is more or less in a transient state all the time. Water and energy are closely related. The role of energy in water and wastewater operations is discussed. With increasing energy costs and the threatening climate changes this issue will grow in importance.

• 대한전기학회논문지:전력기술부문A
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• 제52권7호
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• pp.407-413
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• 2003

Before expanding of distribution automation application to distribution network, we must examine whether there are economical effect. Investment expense for distribution automation can be divided into facility investment expense, maintenance expense, communication expense, investment expense etc. Effect of distribution automation can classify by effect that can convert into money and effect that can not convert into money. Representative effect is outage time decrease effect, distribution line loss decrease effect, main transformer upload effect, distribution line upload effect, work environment improvement effect of lineman and so on. This paper studied economical effect and break-even Point for investment expense by using data that acquire in KEPCO's distribution network.

• 품질경영학회지
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• 제31권4호
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• pp.176-183
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• 2003

The concept of cost of quality has become important economic measures of quality issues for several decades. Most of the research to date has focused on the problem and solution under static business conditions. However, some researchers have found that prevention cost of COQ is one of the expenses of investment and the payback will be shown by the improvement of product quality. These approaches have considered cost of quality issues based on a time factor. It means that there is a trade­off between prevention/appraisal costs and failure costs. Based on a capital budgeting approach, this research reviews the economics of quality improvement activities and proposes the decision criteria to justify quality improvement activities.

• 에너지공학
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• 제10권4호
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• pp.327-334
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• 2001

산업단지와 같은 공장이 많이 밀집되어 있는 곳에서 열은 많이 버려지고 있다. 본 연구는 폐열을 신속하게 이용하기 위하여 폐열을 발굴하여 실재 사업 실행에 이르기 전까지의 내용을 단계적으로 나타내었으며 사업에 직접 적용할 수 있는 폐열 이용방안을 제시하였다. 특히, 열공급처와 수요처의 열공급 및 수요조사를 통하여 상호간의 열 이용을 분석하였으며 열공급 수송의 기본설계를 하였고 열 수요처에 공급하는 열에 대하여 경제성 및 타당성을 검토하였다. 이에 따른 실증분석에 수요처 열사용 투자회수기간은 1,909년으로 비교적 짧은 것으로 나타났다.

• 품질경영학회지
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• 제40권1호
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• pp.39-48
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• 2012

An early detection system for warranty issues periodically collects customers' claim data and automatically reports alarms about emerging issues based on statistical algorithms. It helps companies to reduce an issue definition time and save the handling cost of warranty claims. This paper provides an evaluation framework to validate the economic effect of an early detection system project. For this purpose, we present economical index of a project with explicit formulas such as ROI(return on investment), PP(payback period), NPV(net present value), PI(profitability index) and IRR(internal rate of return) and analyze the sensitivities of the index according to the variation of project input parameters. The proposed analysis framework is expected to be used for evaluating economic values of various system integration projects.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.592-595
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• 2009

In recent years, geothermal heat pump (GHP) systems have become increasingly popular for heating and cooling in buildings. The Standing Column Well (SCW) method is one of the most efficient GHP system. Because it use groundwater for heat transfer material. In SCW systems, water is re-circulated between the well and the building (heat pump). It is only a short time since this method has been applied in domestic. So we have to refer to the developed countries' guides and manuals of SCW. In this paper, several design and construction points of SCW method are filed. We used real operation data of SCW system at Chong-Ju Univ. site for economical efficiency analysis. As a result, the payback period of Chong-Ju Univ. site is calculated at 7.23 years.

• 농촌지도와개발
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• 제5권2호
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• pp.133-142
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• 1998

The purpose of this study was to investigate development derections for upbringing young success farmers. The study was carried out through literature review and questionnarie survey. Total of 400 young success farmers were surveyed to collect data, and 394 responded. For deveolpment directions of upbringing young success farmers, this study suggests; 1) to increase investment of agricultural management and marketing, 2) to postpone the time to payback and to lower the loan rates, 3) to enlarge consulting service in agricultural extension organizations.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 춘계학술발표대회 논문집
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• pp.229-234
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• 2011

Feasibility assessment for small hydropower plants using diversion weirs located in stream for agricultural purpose has been studied. The model, which can predict flow duration characteristic of stream, was developed to analyze the inflow caused from rainfall. And another model to predict hydrologic performance for small hydropower plants is established. Preliminary survey was performed identifying several candidate sites, and two sites were selected finally for actual site reconnaissance. During the course of site survey, generating capacity, construction and equipment cost, and payback through life time of each sites were calculated for economical feasibility analysis. The results of this study have estimated that the small hydropower plants using diversion weirs for agricultural purpose may offer better opportunities in future with increasing fuel cost and nation's energy policy.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2013년도 추계 학술논문 발표대회
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• pp.98-99
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• 2013

Recently, solar control facade systems are highlighted due to its low cost and outstanding applicability for green remodeling. However, it has not been long time since the systems were introduced. Therefore, the application study of the solar control system also has been insufficient. In this study, simulated models were developed and three types of solar control systems(i.e., overhang, blind, and screen)are installed in the models. The efficiency of energy savings and investment payback period according to the application of solar control facade system were analyzed.