• 환경영향평가
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• 제14권6호
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• pp.443-453
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• 2005

For the purpose of the comparative environmental estimation of the incineration processes for domestic wastes, environmental impacts for several incineration processes for one ton of domestic wastes have been estimated by employing life cycle assessment as the environmental impact assessment method. The scheme of minimum production of environmental pollutants has been considered for three different incineration processes. The evaluation for latent influence on environment was carried out by using CML(Center of Environmental Science) method which was developed by University of Leyden in Netherlands based on the equivalency factor suggested by Korea Accreditation Board. The result of life cycle assessment has showed that the total cost analysis according to the amount of incinerating waste was dependent on the operating conditions of incineration process. In addition, the annual running cost for the incineration of one ton of wastes was estimated to be negatively dependent on the amount of wastes. The degree of environmental pollution was mainly due to the kinds of the wastes rather than by the amount of wastes.

• 한국신뢰성학회지:신뢰성응용연구
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• 제17권4호
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• pp.316-324
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• 2017

Purpose: The purpose of this study is to determine the replacement cycle applied age replacement policy by reliability analysis based on railway vehicle contactor's failure history data. Method: We performed reliability analysis based on railway vehicle contactor's failure history data. We found a suitable distribution by goodness of fit test and predicted the reliability through estimation of scale & shape parameter. Considering cost information we determined the replacement cycle that minimize the opportunity cost. Result: Suitable distribution was the Weibull and scale parameter & shape parameter are estimated by reliability analysis. The replacement cycle was predicted and MTTF, $B_6$ percentile life were suggested additionally. Conclusion: We confirmed that failure rate type of railway vehicle contactor is degradation model having a time dependent characteristic and examined the replacement cycle in our country's operating environment. We expect that this study result contribute to railway operation agency for maintenance policy decision.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.232-237
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• 2008

Several research institutes including KISTEC and KRRI etc., recently, have studied maintenance activities and performance, in order to determine proper maintenance level and maintenance cost of rail tracks. But it may extremely difficult to make a decision in maintenance matters of concrete track and ballast containing other sub-components. For these reasons, this study investigate variables related to current maintenance, essential maintenance, and preventive maintenance. It is intended to suggest estimation method of proper maintenance cost maximizing rail track performance. It is stated that proposed approach may be very useful to make a decision of proper maintenance level. Typical section of rail track is applied for calculation of life cycle cost according to each maintenance strategy. A proper profile for maintenance is determined minimum life cycle

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.1299-1305
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• 2006

In this paper, the objective is an evaluation of economics using Life Cycle Cost(LCC) analysis for the ballasted track and the concrete track. However, since the absence of reliable data on maintenance activities, the degree of a reliability about the results of the LCC analysis is insufficient yet. In order to remedy the problems, we surveyed a professional research group for an approximate estimation which can be represented a degree of maintenance through a application of examples. Hereby we found that it is possible to expect the retrenchment of cost using preventive maintenance management. Moreover we proposed appropriate and economical restrictions between track structures.

• 산업공학
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• 제17권spc호
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• pp.122-130
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• 2004

Since the cost of software maintenance occupies about 50~75% in a general successful organization, the software maintenance plays an important role in software life cycle. In particular, if the managed system needs to be operated in a long term or the system is very large and complex, then the maintenance is especially more important. Software maintenance is defined as software modification activities after customer delivery, such as improvement of performance or functionality, error correction, adaptation to environmental changes, etc. In this paper, software cost estimation models are proposed, that is based on productivity of manpower in maintenance projects. In order to do this, the activities of maintenance are classified into function change, non-function change, user support and application operation. The proposed models are constructed and verified based on the real size and cost information of projects in the real world. The approach in this paper is to discriminate the heterogeneous activities in maintenance projects, and then to calculate the respective cost of each discriminated activity. By using the proposed models, the total cost of maintenance project is summed from the costs of four activities. In addition the number of conflicts between owner and order receiver about the amount of cost will be reduced and the reasonable cost estimation system will be established.

• 품질경영학회지
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• 제51권3호
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• pp.461-479
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• 2023

Purpose: It emphasizes the importance of cost analysis for weapons systems that require enormous develop- ment costs, analyzes the problems of cost analysis steps from a practical point of view, and presents the direction of business development in terms of cost analysis reliability, timeliness, and efficiency. Methods: It analyzes the R&D cost of Micro satellites with a complex cost structure and large scale according to engineering estimation procedures, derives major analysis step-by-step problems, and presents business development directions. Results: Problems with standards and assumptions, data collection, cost division structure, and cost estimation methods were derived through the micro satellite cost analysis process, and business development directions such as expanding common standards, standardizing basic data, standardizing cost division structures and cost items, and data asset were presented. Conclusion: In order to develop work in terms of cost analysis reliability, timeliness, and efficiency, it is important to prepare and standardize standards and rules for detailed tasks at each analysis stage, and through this, it is expected that high utilization value and systematic cost data will be assetized in the future.

• 한국시뮬레이션학회논문지
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• 제29권4호
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• pp.85-94
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• 2020

철도교통사업의 계획 및 시행 가능 여부를 판단 하는 데 있어, 다양한 의사결정 과정이 필수적으로 요구되며, 그 결과로 총사업비, 운영비 등을 포함한 LCC(Life Cycle Cost) 값을 예측한다. 본 연구에서는 철도교통사업 의사결정 및 LCC 도출과정을 지원하기 위한 모델링 및 시뮬레이션 기반의 분석 방식을 제안한다. 먼저, 수치적 데이터 기반의 분석이 가능하도록 기존 다양한 철도교통사업 자료를 취합하여 Cost Analysis 모델을 구성하였으며, 실험계획법 및 반응표면법 기반의 근사모델링 기법을 통해 시뮬레이션을 수행, 결과를 도출하여 분석하였다. 모델 구성 및 시뮬레이션을 효과적으로 수행하기 위해 전문적인 상용 소프트웨어 도구를 사용하였다. 연구 결과 검증을 위해 실제 추진되고 있는 철도교통사업을 선정하여 분석결과를 비교하였고, 이를 각 분야 전문가 검증 과정을 거쳐 연구 성과의 신뢰성을 검토하였다.

• Smart Structures and Systems
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• 제13권3호
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• pp.407-418
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• 2014

The purpose of this paper is to present an Integrated Life Cycle Bridge Information Modeling that can be used throughout different phases of the bridge life cycle including: design, construction, and operation and maintenance phases. Bridge Information Modeling (BrIM) has become an effective tool in bridge engineering and construction. It has been used in obtaining accurate shop drawings, cost estimation, and visualization. In this paper, BrIM is used as an integrated tool for bridges life cycle information modeling. In the design phase, BrIM model can be used in obtaining optimum construction methods and performing structural advanced analysis. During construction phase, the model selects the appropriate locations for mobile cranes, monitors the status of precast components, and controls documents. Whereas, it acts as a tool for bridge management system in operation and maintenance phase. The paper provides a detailed description for each use of BrIM model in design, construction, and operation and maintenance phases of bridges. It is proven that BrIM is an effective tool for bridge management systems throughout their life phases.

• 에너지공학
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• 제13권4호
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• pp.296-300
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• 2004

본 연구는 지열원 물 대 물(water to water)히트 펌프 시스템의 냉방 및 난방 운전시 성능 특성과 경제성 평가에 관한 것이다. 5개의 보어홀당 지중 100m의 깊이로 밀폐 수직형 지중 열교환기(closed-vertical ground source)가 설치된 냉난방 시스템이 적용된 건축물에 대하여 냉난방 운전성능을 평가하였으며, 연간 소비전력을 측정하여 실제 시스템의 경제성을 분석하였다. 또한, 순환수의 입구온도에 따른 시스템의 운전 성능을 분석한 결과 난방시에는 COP가 3.0에서 4.2로 증가한 반면, 냉방시에는 5.0에서 3.7로 감소하였다. 본 실험을 통해서,대상 건축물에 대한 지열 냉난방 시스템의 수명주기비용은 기존 냉난방 시스템(보일러+에어컨)에 비해서 68%까지 절감되었으며, 시스템의 경제성을 고려해 볼 때 기존 건축물에도 지열원 냉난방 시스템을 적용하는 것이 타당하다.

• Nuclear Engineering and Technology
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• 제43권2호
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• pp.141-148
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• 2011

This paper presents the quantitative analysis results of research on the burnup effect on the nuclear fuel cycle cost of BeO-$UO_2$ fuel. As a result of this analysis, if the burnup is 60 MWD/kg, which is the limit under South Korean regulations, the nuclear fuel cycle cost is 4.47 mills/kWh at 4.8wt% of Be content for the BeO-$UO_2$ fuel. It is, however, reduced to 3.70 mills/kWh at 5.4wt% of Be content if the burnup is 75MWD/kg. Therefore, it seems very advantageous, in terms of the economic aspect, to develop BeO-$UO_2$ fuel, which does not have any technical problem with its safety and is a high burnup & long life cycle nuclear fuel.