• 한국신뢰성학회지:신뢰성응용연구
• /
• 제15권3호
• /
• pp.145-148
• /
• 2015

The products to meet the requirement of are installed in nuclear power plant and the reliability target should be provided in the requirement. However, it is not easy to set a reliability target using quantitative analysis. The objective of this paper is to propose a method of reliability target setting considered warranty cost for process controller and then compare a reliability target with reliability analysis result.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2000년도 가을 학술발표회논문집
• /
• pp.101-108
• /
• 2000

An optimum design algorithm using efficient reanalysis is proposed for reliability-based optimization problems formulated as the minimization of initial cost and expected failure cost with reliability constraints. The reliability-based optimization is high cost to evaluate objective function and constraints needed reliability analysis. Therefore the sensitivity analysis of reliability index for approximated reanalysis is necessary. In this paper, three solution approaches are suggested and tested. The approaches include : (1) sensitivity analysis using finite difference; (2) sensitivity analysis using automatic differentiation (AD); and (3) sensitivity analysis with respect to intermediate variables using AD. Numerical example is optimized to show the reliability and effectiveness of the new algorithm.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제11권2호
• /
• pp.187-212
• /
• 2011

KHP project sets total ownership cost as the target cost by applying CAIV and administrates total ownership cost through compromise analysis, a periodical estimate and management of design alternatives for each development. Based on expected cost results, sensibility of total ownership cost is analyzed complying with the change of reliability, availability, maintainability and other related factors. By considering potential total ownership cost saving methods, first of all, this paper identifies total ownership cost changing effects for each related factor, secondly, suggests total ownership cost and maintenance and operating cost saving methods via finding components that affect total ownership cost and lastly, suggests total ownership cost saving directions that may be applied to other projects in the future.

• 한국건축시공학회지
• /
• 제8권4호
• /
• pp.53-59
• /
• 2008

Cost estimates are very important to their decision-making in the early stages of a construction project. So Clients have wanted not only to know the results of conceptual cost estimates but also to assess their quality Conceptual cost estimates process is very complex process, so the results of cost estimates are influenced by various factors. So the purpose of this study is to reveal the key factors which influence the reliability of conceptual cost estimates in building construction projects. The analytic hierarchy process is used to determine the relative important weights of elements influencing the conceptual cost estimates. And factor analysis is used to reveal the key factors from the elements that influence the conceptual cost estimates. The results showed that the key factors is an experience level, available data level, level of will for winning the bid, difficulty level of conceptual cost estimate, uncertainty level.

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

• 한국항공우주학회지
• /
• 제40권4호
• /
• pp.364-374
• /
• 2012

본 연구에서는 발사체의 개념설계 단계 동안 성능 변수뿐만 아니라 신뢰성에 따른 개발비용 추정방안을 분석하고자 하였다. 과거에는 발사체의 개발비용을 예측하기 위해서 주로 발사체의 성능과 건조 질량 등을 독립변수로 하는 추정 방법이 많이 이용되었다. 이러한 접근 방법은 비교적 근사하였지만 신뢰성 수준에 따른 비용 변화를 반영할 수 없기 때문에 원하는 신뢰성을 가진 발사체의 개발비용을 근접하게 예측하기는 쉽지 않았다. 본 논문에서는 이러한 비용추정 방법의 한계를 개선하기 위해 성능과 질량을 기반으로 한 비용 모델인 TRANSCOST에 신뢰성 개념을 도입하여 발사체 비용을 추정할 수 있는 방법론을 제시하였다. 이를 기반으로 신뢰성에 따른 한국형발사체(KSLV- II)의 개발비용을 추정했다.

• 한국안전학회지
• /
• 제29권6호
• /
• pp.94-98
• /
• 2014

본 연구는 구조물의 최적안전수준과 수명기간동안 투자되는 총비용과의 상관관계를 연구하였다. 설계, 건설 및 공용 중 투자되는 총비용을 최소화하면서 최적의 안전수준을 결정하기 위하여 신뢰성해석을 수행하였다. 신뢰성해석에는 설계인자들의 불확실성과 설계 및 공사, 유지관리를 수행하는 인간의 오류 등 인적 불확실성을 확률변수로 고려하였다. 이러한 확률해석을 통한 안전지수와 생애주기비용의 상관관계를 연구하고, 생애주기비용의 분산도에 따른 안전지수의 민감도해석을 통하여 최적의 안전수준을 결정하였다. 해석결과는 이러한 평가방법이 교통시설물에 투자되는 비용을 최소화하면서 최적의 안전수준을 결정할 수 있는 정확하고 유용한 방법임을 보여주었다.

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

• Structural Engineering and Mechanics
• /
• 제31권1호
• /
• pp.11-24
• /
• 2009

In China, the oil and natural gas resources of Bohai Bay are mainly marginal oil fields. It is necessary to build both ice-resistant and economical offshore platforms. However, risk is involved in the design, construction, utilization, maintenance of offshore platforms as uncertain events may occur within the life-cycle of a platform under the extreme ice load. In this study, the optimum design model of the expected life-cycle cost for ice-resistant platforms based on cost-effectiveness criterion is proposed. Multiple performance demands of the structure, facilities and crew members, associated with the failure assessment criteria and evaluation functions of costs of construction, consequences of structural failure modes including damage, revenue loss, death and injury as well as discounting cost over time are considered. An efficient approximate method of the global reliability analysis for the offshore platforms is provided, which converts the implicit nonlinear performance function in the conventional reliability analysis to linear explicit one. The proposed life-cycle optimum design formula are applied to a typical ice-resistant platform in Bohai Bay, and the results demonstrate that the life-cycle cost-effective optimum design model is more rational compared to the conventional design.

• 항공우주시스템공학회지
• /
• 제17권5호
• /
• pp.1-10
• /
• 2023

본 연구는 무인항공기에 대한 계획창정비의 최적 주기결정 목표 하에, 신뢰도 및 정비도 분석결과를 활용하여 신뢰도 및 정비도 기반 시뮬레이션과 운영유지 비용분석을 통해 계획창정비 수행의 효용성 (경제성)을 검증하였고, 무인항공기 운영의 효과성과 유지관리 비용의 균형을 맞추는 최적의 계획창정비 주기를 제시하였다.