• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2000년도 추계학술대회 논문집
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• pp.73-78
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• 2000

This paper describes the effect of span-to-depth ratio, which describes aspect of cell formed with top diaphragm steel plate, on capacity in composite steel-concrete structure of sandwich system. The span-to-depth ratio \ulcorner load-carrying mechanism and load-distribution capacity of structure. Therefore, stress levels of members and load-resis\ulcorner of system vary according to span-depth ratio. In this study, numerical nonlinear analysis was performed to various ratio for two types(MA, MB) composite structure of sandwich system to analyze the influence of span-to-depth ratio or, behavior. The difference of load-carrying mechanism and stress of members results from analysis results, then bas\ulcorner differences, the effects of span-to-depth ratio on shear capacity, flexural capacity and load-resistance capacity were analyze effects on failure mode and ductility were briefly. As a results of this study, as span-to-depth ratio increases, \ulcorner bottom steel plate and concrete lower. This implies an increase in effective flexural and shear capacity. Therefore lo\ulcorner capacity of structure improves as span-to-depth ratio increases, Especially, the effect is greate in shear than flexural span-to-depth ratio increases, this difference between flexural and shear capacity may change failure mode and ductility. span-to-depth ratio increases capacity increases more than flexural capacity, we should expect that structural behavior mode gradually change from shear to flexural and ductility of structure gradually improves.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 추계 학술발표회
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• pp.508-518
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• 2008

Reliability and sensitivity analysis of the design parameters for a section of caisson type quaywall which is the most applicable in Korea were performed. It was tried to estimate probabilities of failure for the system of the multiple failure modes and to analyze LCC in the quaywall structure. The reliability analysis was performed by FORM. Also, sensitivity indices were estimated using the reliability indices, which may be used inferring effects of each design parameter on the reliability indices. As a result, the coefficient of friction between caisson and rubble, the moment by self weight and the moment of resistance mostly affected on the reliability indices in the sliding, overturning and foundation failure, respectively. System reliability theorem was applied in order to estimate the probabilities of failure for the system of the multiple failure modes. As the results of estimation of the probabilities of failure for the system, all cases were more conservative than those for the elements, according to both failure mode and load combination applied to series system. It entirely exceeded the target reliability index, but it was consistent with the theorem. According to the optimum LCC with the width of the caisson, the probability of failure exceeded the target probability of failure at then time. Therefore, it was judged to be insufficient to the practical application.

• 한국해양공학회지
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• 제19권5호
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• pp.65-70
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• 2005

Fracture behavior and pipe strength are very important to the integrity of energy plants, ocean structures, and so forth. The pipes of energy plants and ocean structures are subject to local wall thinning, resulting from severe erosion-corrosion damage. Recently, the effects of local wall thinning on fracture strength and fracture behavior of piping systems have been the focus of many studies. In this paper, the elasto-plastic analysis is performed by FE code ANSYS on straight pipes with wall thinning. We evaluated the failure mode, fracture strength and fracture behavior, using FE analysis. Also, the effect of the axial strain on deformations and failure modes was estimated by FE analysis.

• 한국멀티미디어학회논문지
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• 제18권11호
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• pp.1342-1350
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• 2015

Due to rapid development of mobile device technologies, the mobile banking through Internet has become a major service of banking information systems as a security-critical information systems. Recently, lots of mobile banking information systems which handle personal and transaction information have been exposed to security threats in vulnerable security control and management processes, mainly software systems. Therefore, in this paper, we propose a process model for software security improvements in mobile banking information system by application of fault tree analysis(FTA) and failure modes and effects analysis(FMEA) on the most important activities such as 'user authentication' and 'access control' and 'virus detection and control' processes which security control and management of mobile banking information systems are very weak.

• 벤처창업연구
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• 제7권3호
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• pp.133-141
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• 2012

글로벌 경쟁 상황에 처한 현대의 모든 기업들은 고객의 니즈를 충족시키고, 이를 통한 경쟁력을 강화하기 위한 방안으로서 서비스를 이해하기 시작하면서 서비스에 대한 관심이 날로 증가하고 있다. 기업들이 제공하는 제품이나 서비스의 가치는 주로 고객과 서비스 제공자 간의 관계에서 형성되는 만족도의 정도로 정의되는 서비스 신뢰도에 의해 크게 좌우된다. 본 연구에서는, 유형의 제품이나 시스템의 실패 유형과 영향을 평가하는데 널리 사용되는 FMEA를 서비스의 신뢰도 평가에 적용하였다. 이를 위해, 서비스의 설계와 서비스 기능과 실패 간의 관계를 용이하게 표현할 수 있는 사건중심 프로세스 모델을 이용하였다. 본 연구의 목적은 서비스 프로세스 관점에서의 서비스 신뢰도를 평가하는 방법을 제시하는 것으로서, 이를 위해 fuzzy FMEA와 grey 이론을 이용하였다. 제안된 방법은 자동차정비 프로세스 사례에 적용하여 평가하였다.

• 한국해양공학회지
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• 제23권6호
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• pp.32-38
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• 2009

An FMEA for the waterjet-lifter of a DSNM is performed to prevent the occurrence of device failure. A waterjet-lifter raises and transports manganese nodules from the deep-sea floor up to a somewhat elevated place, from which a pin-scraper transports the lifted nodules to the inner space of the DSNM. A concept design for a device using the axiomatic design methodology is shown as the mapping between the functional domain and physical domain. The FMEA for a DSNM is introduced briefly and the rating criteria of severity, occurrence, and detection for the DSNM are defined. The FMEA of the functional requirements of a DSNM device is accomplished. Three kinds of failure modes, as well as their effects and causes, are predicted. Current design control methods for detecting potential failures, such as physical or computational experiments, design confirmation, and mathematical calculation, are described and the recommended actions for several significant causes are suggested.

• 품질경영학회지
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• 제45권4호
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• pp.665-676
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• 2017

Purpose: The purpose of this paper proposes an effective and systematic methods of risk management in product development project. Methods: This paper first discusses what risk factors be considered during product development period and then presented a model for preventive risk management. For that, this paper proposes how to evaluate the risk factors and risk events, and how to select prevention action for managing risk factors effectively. For this process, this paper uses well-known quality tools such as House of Quality (HOQ) and Failure Mode and Effects Criticality Analysis (FMECA) methods. Results: There is an inherent need for the development of robust risk management framework in order for product development projects to be successful. The identification and quantification of risk factors, risk events, and prevention actions can have significant effects on the success of a product development projects. Project managers can implement the proposed model to improve project success. Conclusion: The findings showed that this method would be effective for project managements in dealing with risk management issues in product development projects. This method presented would be an one of good guidelines for practitioners in the industry.

• Journal of Construction Engineering and Project Management
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• 제6권2호
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• pp.24-29
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• 2016

This paper elaborates the significance of scenario planning in risk management, and presents an integrated approach which takes into account the 'Risk Events' derived from scenario planning for risk prioritisation. This research integrates scenario planning with Risk Failure Mode and Effect Analysis (RFMEA) through examples from construction litigations of project schedule and cost overrun cases as a simplified approach to project risk management. The proposed methodology incorporates scenarios developed from realistic events of dispute and arbitration cases from construction projects, and thereby increasing potential to foresee risks and their effects well in advance. The results from this methodology shall be validated against outcome of survey study conducted by KPMG-PMI (2013) on project schedule and cost overruns that was based on Ministry of Statistics and Programme Implementation (MoSPI) Project Monitoring data for 2012-13.

• 한국항공운항학회지
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• 제21권4호
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• pp.27-33
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• 2013

In this study, the FMEA and FTA for reliability analysis of hybrid rocket motor are performed, that was designed in the Hybrid Rocket Propulsion Laboratory of Korea Aerospace University. In order to carry out these analyses the structure of the hybrid rocket motor is hierarchically divided into 36 parts down to the component level and FMEA is carried out with 72 failure modes. Reliability is assessed based on the FMEA, and the results are used in the FTA to evaluate the overall system reliability. In the FMEA, the relationship between the cause and failure modes, effects and their risk priorities are evaluated qualitatively. 27 failure modes are chosen as those with the critical severity that should be improved with priority. As a result of the FMEA / FTA study, a series of design or material changes are made for the improvement of reliability.

• 한국지반공학회논문집
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• 제20권8호
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• pp.193-203
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• 2004

표면이 거친 강성옹벽의 경우 뒷채움재에서 발생하는 아칭효과로 인해 옹벽에는 비선형의 토압분포가 작용하며, 아칭효과가 비선형의 토압분포에 미치는 영향은 옹벽의 변위 형태에 따라 달라진다. 따라서 강성옹벽에 작용하는 주동토압의 크기와 비선형의 토압분포를 정확하게 산정하기 위해서는 옹벽의 변위형태에 따라 달라지는 뒷채움재에 서 발생하는 실제적 인 파괴면 형상과 아칭효과를 고려해야만 한다. 따라서 본 연구에서는 강성옹벽이 저점을 중심으로 회전하는 경우에 뒷채움재에서의 아칭효과와 비선형의 파괴면 형상을 고려함으로써 비선형의 주동토압을 산정할 수 있는 토압산정식을 제안하였다. 이 과정에서 토압산정식이 수학적으로 복잡해지는 것을 피하기 위하여 뒷채움재에서 발생하는 비선형의 파괴면 형상은 4개의 직선으로 구성되는 가상의 파괴면으로 대체하였다. 그리고 제안식으로부터 구한 예측치를 기존의 모형시험 결과와 비교한 결과 제안식은 만족스런 토압 예측치를 제공하는 것으로 나타났다.