• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
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• pp.159-160
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• 2018

The domestic construction industry is changing its preference for demand and supply along with urbanization and economic development. Accordingly, initial risk assessments is more important than before. Currently, the research related to risk analysis except for apartment studies is insufficient. Therefore, the objective is to suggest a basic study on financial analysis model development by applying optimization method in residential officetel. To achieve the objective. first, the previous studies are investigated. Second, the causal loop diagram is structured based on the collected data. Third, the financial model is developed by using optimization method. In the future, the proposed model can be helpful whether or not conduct execution of an officetel development project to the decision makers.

• 한국건설관리학회논문집
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• 제15권3호
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• pp.113-119
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• 2014

LCC 분석은 건축물의 설계단계 뿐만 아니라 유지관리 단계에서의 보수 보강 또는 교체에 대한 최적 의사결정의 도구로서 이론적으로나 실무적으로 각광을 받고 있는 분석 방법이다. 이는 초기 투자비용의 효율성을 극대화 하고 유지관리를 통한 구조물 사용성의 효율적 증대를 극대화하는 노력의 일환으로 최근 건축물의 설계 및 유지관리 시 LCC 분석효과의 실질적인 적용이 요구되어 지고 있다. 따라서 본 논문은 일반적인 분석기법에 그치고 있는 기존 LCC 연구를 생애위험도를 고려한 LCC분석을 통해 설계단계 최적 의사결정을 위한 새로운 분석 방법론을 도출하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.971-976
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• 2004

The management of railroad structures is more difficult and complicate because there are many structures such as rail, bridge, tunnel, station, and so on. Therefore, LCC(Life Cycle Cost) analysis of railroad structures as public infrastructure must contain a maintenance cost as well as an initial cost in order to make a more effective management during the life cycle on the design phase. This paper presents a cost classification scheme considering user costs such as value of delayed time of passenger and freight. Also, in this study it is developed a probabilistic life cycle cost(PLCC) analysis model of railroad structures taking into account uncertainties and variations of input variables in order to analyze LCC. It may be stated that the model proposed in this study can greatly contribute to the making optimal decision, the estimate of the maintenance cost and the allocate of budget in the project of railroad structures.

• 대한토목학회논문집
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• 제34권2호
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• pp.645-654
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• 2014

현재 우리나라 일반국도의 포장관리시스템(PMS: Pavement Management System)은 세계은행(World Bank)이 주도한 HDM (Highway Development and Management)-4를 사용하여 유지보수 의사결정의 기초 자료로 사용하고 있으나, 과다한 입력변수와 모형의 불확실성 등으로 인해 국내 실정에 적합한 경제성 분석모형이 필요하게 되었으며, 대부분의 선진국의 경우에는 각 지역과 국가에 맞는 PMS 시스템을 구축하여 운영하고 있다. 따라서 본 연구에서는 우리나라 실정에 맞고 효율적인 국도의 도로 및 포장관리를 위한 의사결정시스템을 개발하기 위한 연구로써 시스템 개발에 필요한 구성요소, 공용성 모형 개발, 각 요소별 활용가능한 원단위, 기준 등의 지표 정의 및 종류, 특성들을 분석, 정리하고 경제성 평가를 통해 최적 의사결정을 위한 시스템(S/W) 개발을 목적으로 하였다. 포장관리를 위해 개발한 의사결정시스템의 구성요소는 크게 1)도로, 교통, 사회경제 지표 등의 DB, 2) 도로포장상태의 공용성 모형, 3)도로포장상태에 따른 차량속도변화 모형, 4)경제성 평가 모형, 5) 의사결정지원 시스템으로 구성되며, 개발된 시스템의 검증을 위해 사례 구간을 대상으로 한 분석결과도 함께 제시하였다. 그러나 장래 확률적 특성을 고려한 공용성 모형의 개발과 의사결정을 위한 지표 개발에 대해서는 추가적인 연구가 필요할 것으로 판단된다.

• Earthquakes and Structures
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• 제11권4호
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• pp.583-607
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• 2016

One of the main applications of seismic risk assessment is that an specific design could be selected for a bridge from different alternatives by considering damage losses alongside primary construction costs. Therefore, in this paper, the focus is on selecting the shape of pylon, which is a changeable component in the design of a cable-stayed bridge, as a double criterion decision-making problem. Different shapes of pylons include H, A, Y, and diamond shape, and the two criterion are construction costs and probable earthquake losses. In this research, decision-making is performed by using developed seismic risk assessment process as a powerful method. Considering the existing uncertainties in seismic risk assessment process, the combined incremental dynamic analysis (IDA) and uniform design (UD) based fragility assessment method is proposed, in which the UD method is utilized to provide the logical capacity models of the structure, and the IDA method is employed to give the probabilistic seismic demand model of structure. Using the aforementioned models and by defining damage states, the fragility curves of the bridge system are obtained for the different pylon shapes usage. Finally, by combining the fragility curves with damage losses and implementing the proposed cost-loss-benefit (CLB) method, the seismic risk assessment process is developed with financial-comparative approach. Thus, the optimal shape of the pylon can be determined using double criterion decision-making. The final results of decision-making study indicate that the optimal pylon shapes for the studied span of cable-stayed bridge are, respectively, H shape, diamond shape, Y shape, and A shape.

• Nuclear Engineering and Technology
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• 제47권2호
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• pp.204-211
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• 2015

Probabilistic safety assessment (PSA) has had a significant role in quantitative decision-making by finding design and operational vulnerabilities and evaluating cost-benefit in improving such weak points. In particular, it has been widely used as the core methodology for risk-informed applications (RIAs). Even though the nature of PSA seeks realistic results, there are still "conservative" aspects. One of the sources for the conservatism is the assumptions of safety analysis and the estimation of failure frequency. Surveillance, diagnosis, and prognosis (SDP), utilizing massive databases and information technology, is worth highlighting in terms of its capability for alleviating the conservatism in conventional PSA. This article provides enabling techniques to solidify a method to provide time- and condition-dependent risks by integrating a conventional PSA model with condition monitoring and prognostics techniques. We will discuss how to integrate the results with frequency of initiating events (IEs) and probability of basic events (BEs). Two illustrative examples will be introduced: (1) how the failure probability of a passive system can be evaluated under different plant conditions and (2) how the IE frequency for a steam generator tube rupture (SGTR) can be updated in terms of operating time. We expect that the proposed model can take a role of annunciator to show the variation of core damage frequency (CDF) depending on operational conditions.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제16권2호
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• pp.87-94
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• 2016

In this paper, we discuss a gait representation based on the width of silhouette in terms of discriminative power and robustness against the noise in silhouette image for gait recognition. Its sensitivity to the noise in silhouette image are rigorously analyzed using probabilistic noisy silhouette model. In addition, we develop a gait recognition system using width representation and identify subjects using the decision level fusion based on majority voting. Experiments on CASIA gait dataset A and the SOTON gait database demonstrate the recognition performance with respect to the noise level added to the silhouette image.

• 한국안전학회지
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• 제30권3호
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• pp.100-106
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• 2015

A module or independent subtree is a part of a fault tree whose child gates or basic events are not repeated in the remaining part of the fault tree. Modules are necessarily employed in order to reduce the computational costs of fault tree quantification. This quantification generates fault tree solutions such as minimal cut sets, minimal path sets, or binary decision diagrams (BDDs), and then, calculates top event probability and importance measures. This paper presents a new linear time algorithm to detect modules of large fault trees. It is shown through benchmark tests that the new method proposed in this study can very quickly detect the modules of a huge fault tree. It is recommended that this method be implemented into fault tree solvers for efficient probabilistic safety assessment (PSA) of nuclear power plants.

• 한국농공학회논문집
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• 제54권6호
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• pp.39-44
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• 2012

Water supply capacity and operational capability in agricultural reservoirs are expressed differently in the limited storage due to seasonal and local variation of precipitation. Since agricultural water supply and demand basically assumes the uncertainty of hydrological phenomena, it is necessary to improve probabilistic approach for potential risk assessment of water supply capacity in reservoir for enhanced operational storage management. Here, it was introduced the irrigation vulnerability characteristic curves to represent the water supply capacity corresponding to probability distribution of the water demand from the paddy field and water supply in agricultural reservoir. Irrigation vulnerability probability was formulated using reliability analysis method based on water supply and demand probability distribution. The lower duration of irrigation vulnerability probability defined as the time period requiring intensive water management, and it will be considered to assessment tools as a risk mitigated water supply planning in decision making with a limited reservoir storage.

• 상하수도학회지
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• 제24권2호
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• pp.183-193
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• 2010

Well planned rehabilitation order of pipes is essential for efficient maintenance and management of Water Distribution Systems. In this study, not only deterioration rate of pipes but also structural and nonstructural failure which causes abnormal condition of WDS is considered to determine rehabilitation order. Probabilistic Neural Network is used for calculating deterioration rate at present and the importance of pipes is computed under structural and nonstructural failure by using Pipe by Pipe Failure Analysis and Effect Index. Utopian Approach, one of the Multi-Criteria Decision Making methods, is used for assessment of final rehabilitation order based on distance measure between utopian point and alternative one. Developed model in this study shows that it gives more reliable results than existing methods considering hydraulic relative importance does in application to real networks. In this point, the newly developed model, which gives advantages over existing models, can make a credible decision and simple application.